diff --git a/Engine.Core/Collectors/ActiveBehaviourCollectorOrdered.cs b/Engine.Core/Collectors/ActiveBehaviourCollectorOrdered.cs
index 502e45c..927d009 100644
--- a/Engine.Core/Collectors/ActiveBehaviourCollectorOrdered.cs
+++ b/Engine.Core/Collectors/ActiveBehaviourCollectorOrdered.cs
@@ -5,9 +5,8 @@ namespace Engine.Core;
 
 public class ActiveBehaviourCollectorOrdered<TIndex, TItem> : ActiveBehaviourCollector<TItem> where TItem : class, IBehaviour where TIndex : IComparable
 {
-    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
-
     private readonly SortedDictionary<TIndex, FastList<TItem>> behaviours = null!;
+    private readonly Dictionary<TItem, TIndex> indexCache = [];
 
     private readonly Func<TItem, TIndex> getIndexFunc = null!;
     private readonly IComparer<TIndex> sortBy = null!;
@@ -39,11 +38,10 @@ public class ActiveBehaviourCollectorOrdered<TIndex, TItem> : ActiveBehaviourCol
 
     protected override bool RemoveBehaviour(TItem tBehaviour)
     {
-        TIndex index = getIndexFunc(tBehaviour);
-        if (!behaviours.TryGetValue(index, out FastList<TItem>? list))
+        if (!indexCache.TryGetValue(tBehaviour, out TIndex? index) || !behaviours.TryGetValue(index, out FastList<TItem>? list))
             throw new Exceptions.NotFoundException($"Index of '{index}' is not found in the collector");
 
-        if (!list.Remove(tBehaviour))
+        if (!list.Remove(tBehaviour) || !indexCache.Remove(tBehaviour))
             return false;
 
         count--;
@@ -58,21 +56,11 @@ public class ActiveBehaviourCollectorOrdered<TIndex, TItem> : ActiveBehaviourCol
 
         count++;
         list.Add(behaviour);
-    }
-
-    protected override void OnBehaviourAdd(IBehaviour behaviour) => behaviour.OnPriorityChanged.AddListener(delegateOnPriorityChanged);
-    protected override void OnBehaviourRemove(IBehaviour behaviour) => behaviour.OnPriorityChanged.RemoveListener(delegateOnPriorityChanged);
-
-    private void OnPriorityChanged(IBehaviour sender, IBehaviour.PriorityChangedArguments args)
-    {
-        TItem behaviour = (TItem)sender;
-        RemoveBehaviour(behaviour);
-        AddBehaviour(behaviour);
+        indexCache.Add(behaviour, key);
     }
 
     public ActiveBehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy)
     {
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.getIndexFunc = getIndexFunc;
         this.sortBy = Comparer<TIndex>.Create(sortBy);
         behaviours = new(this.sortBy);
@@ -80,7 +68,6 @@ public class ActiveBehaviourCollectorOrdered<TIndex, TItem> : ActiveBehaviourCol
 
     public ActiveBehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy) : base(universe)
     {
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.getIndexFunc = getIndexFunc;
         this.sortBy = Comparer<TIndex>.Create(sortBy);
         behaviours = new(this.sortBy);
@@ -89,14 +76,12 @@ public class ActiveBehaviourCollectorOrdered<TIndex, TItem> : ActiveBehaviourCol
     public ActiveBehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy)
     {
         this.getIndexFunc = getIndexFunc;
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.sortBy = sortBy;
         behaviours = new(sortBy);
     }
 
     public ActiveBehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy) : base(universe)
     {
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.getIndexFunc = getIndexFunc;
         this.sortBy = sortBy;
         behaviours = new(sortBy);
diff --git a/Engine.Core/Collectors/BehaviourCollectorOrdered.cs b/Engine.Core/Collectors/BehaviourCollectorOrdered.cs
index 6f1077a..4fe27ff 100644
--- a/Engine.Core/Collectors/BehaviourCollectorOrdered.cs
+++ b/Engine.Core/Collectors/BehaviourCollectorOrdered.cs
@@ -5,9 +5,8 @@ namespace Engine.Core;
 
 public class BehaviourCollectorOrdered<TIndex, TItem> : BehaviourCollectorBase<TItem> where TItem : class where TIndex : IComparable
 {
-    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
-
     private readonly SortedDictionary<TIndex, FastList<TItem>> behaviours = null!;
+    private readonly Dictionary<TItem, TIndex> indexCache = null!;
 
     private readonly Func<TItem, TIndex> getIndexFunc = null!;
     private readonly IComparer<TIndex> sortBy = null!;
@@ -39,11 +38,10 @@ public class BehaviourCollectorOrdered<TIndex, TItem> : BehaviourCollectorBase<T
 
     protected override bool RemoveBehaviour(TItem tBehaviour)
     {
-        TIndex index = getIndexFunc(tBehaviour);
-        if (!behaviours.TryGetValue(index, out FastList<TItem>? list))
+        if (!indexCache.TryGetValue(tBehaviour, out TIndex? index) || !behaviours.TryGetValue(index, out FastList<TItem>? list))
             throw new Exceptions.NotFoundException($"Index of '{index}' is not found in the collector");
 
-        if (!list.Remove(tBehaviour))
+        if (!list.Remove(tBehaviour) || !indexCache.Remove(tBehaviour))
             return false;
 
         count--;
@@ -58,21 +56,11 @@ public class BehaviourCollectorOrdered<TIndex, TItem> : BehaviourCollectorBase<T
 
         count++;
         list.Add(behaviour);
-    }
-
-    protected override void OnBehaviourAdd(IBehaviour behaviour) => behaviour.OnPriorityChanged.AddListener(delegateOnPriorityChanged);
-    protected override void OnBehaviourRemove(IBehaviour behaviour) => behaviour.OnPriorityChanged.RemoveListener(delegateOnPriorityChanged);
-
-    private void OnPriorityChanged(IBehaviour sender, IBehaviour.PriorityChangedArguments args)
-    {
-        TItem behaviour = (TItem)sender;
-        RemoveBehaviour(behaviour);
-        AddBehaviour(behaviour);
+        indexCache.Add(behaviour, key);
     }
 
     public BehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy)
     {
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.getIndexFunc = getIndexFunc;
         this.sortBy = Comparer<TIndex>.Create(sortBy);
         behaviours = new(this.sortBy);
@@ -80,7 +68,6 @@ public class BehaviourCollectorOrdered<TIndex, TItem> : BehaviourCollectorBase<T
 
     public BehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy) : base(universe)
     {
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.getIndexFunc = getIndexFunc;
         this.sortBy = Comparer<TIndex>.Create(sortBy);
         behaviours = new(this.sortBy);
@@ -89,14 +76,12 @@ public class BehaviourCollectorOrdered<TIndex, TItem> : BehaviourCollectorBase<T
     public BehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy)
     {
         this.getIndexFunc = getIndexFunc;
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.sortBy = sortBy;
         behaviours = new(sortBy);
     }
 
     public BehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy) : base(universe)
     {
-        delegateOnPriorityChanged = OnPriorityChanged;
         this.getIndexFunc = getIndexFunc;
         this.sortBy = sortBy;
         behaviours = new(sortBy);