diff --git a/Cargo.lock b/Cargo.lock
index 4f236b51b..6e324f522 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4108,6 +4108,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_with",
+ "strum",
  "thiserror",
  "tokio",
  "tracing",
diff --git a/crates/pool/src/mempool/mod.rs b/crates/pool/src/mempool/mod.rs
index 98a8cedc3..0a8827570 100644
--- a/crates/pool/src/mempool/mod.rs
+++ b/crates/pool/src/mempool/mod.rs
@@ -37,7 +37,6 @@ use ethers::types::{Address, H256, U256};
 use mockall::automock;
 use rundler_sim::{EntityInfos, MempoolConfig, PrecheckSettings, SimulationSettings};
 use rundler_types::{Entity, EntityType, EntityUpdate, UserOperation, ValidTimeRange};
-use strum::IntoEnumIterator;
 use tonic::async_trait;
 pub(crate) use uo_pool::UoPool;
 
@@ -215,9 +214,11 @@ pub struct PaymasterMetadata {
 impl PoolOperation {
     /// Returns true if the operation contains the given entity.
     pub fn contains_entity(&self, entity: &Entity) -> bool {
-        self.entity_address(entity.kind)
-            .map(|address| address == entity.address)
-            .unwrap_or(false)
+        if let Some(e) = self.entity_infos.get(entity.kind) {
+            e.address == entity.address
+        } else {
+            false
+        }
     }
 
     /// Returns true if the operation requires the given entity to stake.
@@ -239,48 +240,31 @@ impl PoolOperation {
 
     /// Returns an iterator over all entities that are included in this operation.
     pub fn entities(&'_ self) -> impl Iterator<Item = Entity> + '_ {
-        EntityType::iter().filter_map(|entity| {
-            self.entity_address(entity)
-                .map(|address| Entity::new(entity, address))
-        })
+        self.entity_infos
+            .entities()
+            .map(|(t, entity)| Entity::new(t, entity.address))
     }
 
-    /// Returns an iterator over all entities that need stake in this operation.
+    /// Returns an iterator over all entities that need stake in this operation. This can be a subset of entities that are staked in the operation.
     pub fn entities_requiring_stake(&'_ self) -> impl Iterator<Item = Entity> + '_ {
-        EntityType::iter()
-            .filter(|entity| self.requires_stake(*entity))
-            .filter_map(|entity| {
-                self.entity_address(entity)
-                    .map(|address| Entity::new(entity, address))
-            })
+        self.entity_infos.entities().filter_map(|(t, entity)| {
+            if self.requires_stake(t) {
+                Entity::new(t, entity.address).into()
+            } else {
+                None
+            }
+        })
     }
 
     /// Return all the unstaked entities that are used in this operation.
     pub fn unstaked_entities(&'_ self) -> impl Iterator<Item = Entity> + '_ {
-        let mut unstaked_entities = vec![];
-        if !self.entity_infos.sender.is_staked {
-            unstaked_entities.push(Entity::new(
-                EntityType::Account,
-                self.entity_infos.sender.address,
-            ))
-        }
-        if let Some(factory) = self.entity_infos.factory {
-            if !factory.is_staked {
-                unstaked_entities.push(Entity::new(EntityType::Factory, factory.address))
+        self.entity_infos.entities().filter_map(|(t, entity)| {
+            if entity.is_staked {
+                None
+            } else {
+                Entity::new(t, entity.address).into()
             }
-        }
-        if let Some(paymaster) = self.entity_infos.paymaster {
-            if !paymaster.is_staked {
-                unstaked_entities.push(Entity::new(EntityType::Paymaster, paymaster.address))
-            }
-        }
-        if let Some(aggregator) = self.entity_infos.aggregator {
-            if !aggregator.is_staked {
-                unstaked_entities.push(Entity::new(EntityType::Aggregator, aggregator.address))
-            }
-        }
-
-        unstaked_entities.into_iter()
+        })
     }
 
     /// Compute the amount of heap memory the PoolOperation takes up.
@@ -289,19 +273,12 @@ impl PoolOperation {
             + self.uo.heap_size()
             + self.entities_needing_stake.len() * std::mem::size_of::<EntityType>()
     }
-
-    fn entity_address(&self, entity: EntityType) -> Option<Address> {
-        match entity {
-            EntityType::Account => Some(self.uo.sender),
-            EntityType::Paymaster => self.uo.paymaster(),
-            EntityType::Factory => self.uo.factory(),
-            EntityType::Aggregator => self.aggregator,
-        }
-    }
 }
 
 #[cfg(test)]
 mod tests {
+    use rundler_sim::EntityInfo;
+
     use super::*;
 
     #[test]
@@ -326,7 +303,24 @@ mod tests {
             sim_block_number: 0,
             entities_needing_stake: vec![EntityType::Account, EntityType::Aggregator],
             account_is_staked: true,
-            entity_infos: EntityInfos::default(),
+            entity_infos: EntityInfos {
+                factory: Some(EntityInfo {
+                    address: factory,
+                    is_staked: false,
+                }),
+                sender: EntityInfo {
+                    address: sender,
+                    is_staked: false,
+                },
+                paymaster: Some(EntityInfo {
+                    address: paymaster,
+                    is_staked: false,
+                }),
+                aggregator: Some(EntityInfo {
+                    address: aggregator,
+                    is_staked: false,
+                }),
+            },
         };
 
         assert!(po.requires_stake(EntityType::Account));
@@ -334,11 +328,6 @@ mod tests {
         assert!(!po.requires_stake(EntityType::Factory));
         assert!(po.requires_stake(EntityType::Aggregator));
 
-        assert_eq!(po.entity_address(EntityType::Account), Some(sender));
-        assert_eq!(po.entity_address(EntityType::Paymaster), Some(paymaster));
-        assert_eq!(po.entity_address(EntityType::Factory), Some(factory));
-        assert_eq!(po.entity_address(EntityType::Aggregator), Some(aggregator));
-
         let entities = po.entities().collect::<Vec<_>>();
         assert_eq!(entities.len(), 4);
         for e in entities {
diff --git a/crates/pool/src/mempool/pool.rs b/crates/pool/src/mempool/pool.rs
index 9b317b321..b93aeed4c 100644
--- a/crates/pool/src/mempool/pool.rs
+++ b/crates/pool/src/mempool/pool.rs
@@ -601,6 +601,8 @@ impl PoolMetrics {
 
 #[cfg(test)]
 mod tests {
+    use rundler_sim::{EntityInfo, EntityInfos};
+
     use super::*;
 
     #[test]
@@ -784,6 +786,10 @@ mod tests {
         ];
         for mut op in ops.into_iter() {
             op.aggregator = Some(agg);
+            op.entity_infos.aggregator = Some(EntityInfo {
+                address: agg,
+                is_staked: false,
+            });
             pool.add_operation(op.clone(), None).unwrap();
         }
         assert_eq!(pool.by_hash.len(), 3);
@@ -805,6 +811,10 @@ mod tests {
         ];
         for mut op in ops.into_iter() {
             op.uo.paymaster_and_data = paymaster.as_bytes().to_vec().into();
+            op.entity_infos.paymaster = Some(EntityInfo {
+                address: op.uo.paymaster().unwrap(),
+                is_staked: false,
+            });
             pool.add_operation(op.clone(), None).unwrap();
         }
         assert_eq!(pool.by_hash.len(), 3);
@@ -839,8 +849,20 @@ mod tests {
 
         let mut op = create_op(sender, 0, 1);
         op.uo.paymaster_and_data = paymaster.as_bytes().to_vec().into();
+        op.entity_infos.paymaster = Some(EntityInfo {
+            address: op.uo.paymaster().unwrap(),
+            is_staked: false,
+        });
         op.uo.init_code = factory.as_bytes().to_vec().into();
+        op.entity_infos.factory = Some(EntityInfo {
+            address: op.uo.factory().unwrap(),
+            is_staked: false,
+        });
         op.aggregator = Some(aggregator);
+        op.entity_infos.aggregator = Some(EntityInfo {
+            address: aggregator,
+            is_staked: false,
+        });
 
         let count = 5;
         let mut hashes = vec![];
@@ -937,6 +959,10 @@ mod tests {
         let mut po1 = create_op(sender, 0, 10);
         po1.uo.max_priority_fee_per_gas = 10.into();
         po1.uo.paymaster_and_data = paymaster1.as_bytes().to_vec().into();
+        po1.entity_infos.paymaster = Some(EntityInfo {
+            address: po1.uo.paymaster().unwrap(),
+            is_staked: false,
+        });
         let _ = pool.add_operation(po1, None).unwrap();
         assert_eq!(pool.address_count(&paymaster1), 1);
 
@@ -944,6 +970,10 @@ mod tests {
         let mut po2 = create_op(sender, 0, 11);
         po2.uo.max_priority_fee_per_gas = 11.into();
         po2.uo.paymaster_and_data = paymaster2.as_bytes().to_vec().into();
+        po2.entity_infos.paymaster = Some(EntityInfo {
+            address: po2.uo.paymaster().unwrap(),
+            is_staked: false,
+        });
         let _ = pool.add_operation(po2.clone(), None).unwrap();
 
         assert_eq!(pool.address_count(&sender), 1);
@@ -1038,8 +1068,18 @@ mod tests {
                 sender,
                 nonce: nonce.into(),
                 max_fee_per_gas: max_fee_per_gas.into(),
+
                 ..UserOperation::default()
             },
+            entity_infos: EntityInfos {
+                factory: None,
+                sender: EntityInfo {
+                    address: sender,
+                    is_staked: false,
+                },
+                paymaster: None,
+                aggregator: None,
+            },
             ..PoolOperation::default()
         }
     }
diff --git a/crates/sim/Cargo.toml b/crates/sim/Cargo.toml
index 43423d71e..7e6ba4faf 100644
--- a/crates/sim/Cargo.toml
+++ b/crates/sim/Cargo.toml
@@ -27,6 +27,7 @@ reqwest.workspace = true
 tokio = { workspace = true, features = ["macros"] }
 tracing.workspace = true
 url.workspace = true
+strum.workspace = true
 
 mockall = {workspace = true, optional = true }
 
diff --git a/crates/sim/src/simulation/simulation.rs b/crates/sim/src/simulation/simulation.rs
index dd2d7560b..19cb56c0c 100644
--- a/crates/sim/src/simulation/simulation.rs
+++ b/crates/sim/src/simulation/simulation.rs
@@ -32,6 +32,7 @@ use rundler_types::{
     contracts::i_entry_point::FailedOp, Entity, EntityType, StorageSlot, UserOperation,
     ValidTimeRange,
 };
+use strum::IntoEnumIterator;
 
 use super::{
     mempool::{match_mempools, AllowEntity, AllowRule, MempoolConfig, MempoolMatchResult},
@@ -798,6 +799,11 @@ impl EntityInfos {
         }
     }
 
+    /// Get iterator over the entities
+    pub fn entities(&'_ self) -> impl Iterator<Item = (EntityType, EntityInfo)> + '_ {
+        EntityType::iter().filter_map(|t| self.get(t).map(|info| (t, info)))
+    }
+
     fn override_is_staked(&mut self, allow_unstaked_addresses: &HashSet<Address>) {
         if let Some(mut factory) = self.factory {
             factory.override_is_staked(allow_unstaked_addresses)
@@ -811,7 +817,8 @@ impl EntityInfos {
         }
     }
 
-    fn get(self, entity: EntityType) -> Option<EntityInfo> {
+    /// Get the EntityInfo of a specific entity
+    pub fn get(self, entity: EntityType) -> Option<EntityInfo> {
         match entity {
             EntityType::Factory => self.factory,
             EntityType::Account => Some(self.sender),