diff --git a/OpenRA.Mods.RA/AI/AttackOrFleeFuzzy.cs b/OpenRA.Mods.RA/AI/AttackOrFleeFuzzy.cs
index 59f1ef4781..273f02739f 100644
--- a/OpenRA.Mods.RA/AI/AttackOrFleeFuzzy.cs
+++ b/OpenRA.Mods.RA/AI/AttackOrFleeFuzzy.cs
@@ -10,6 +10,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using AI.Fuzzy.Library;
 using OpenRA.Mods.RA.Move;
 using OpenRA.Traits;
@@ -165,7 +166,7 @@ namespace OpenRA.Mods.RA.AI
 				"then AttackOrFlee is Flee");
 		}
 
-		public void CalculateFuzzy(List<Actor> ownUnits, List<Actor> enemyUnits)
+		public void CalculateFuzzy(IEnumerable<Actor> ownUnits, IEnumerable<Actor> enemyUnits)
 		{
 			var inputValues = new Dictionary<FuzzyVariable, double>();
 			inputValues.Add(fuzzyEngine.InputByName("OwnHealth"), (double)NormalizedHealth(ownUnits, 100));
@@ -176,7 +177,7 @@ namespace OpenRA.Mods.RA.AI
 			result = fuzzyEngine.Calculate(inputValues);
 		}
 
-		protected float NormalizedHealth(List<Actor> actors, float normalizeByValue)
+		protected float NormalizedHealth(IEnumerable<Actor> actors, float normalizeByValue)
 		{
 			var sumOfMaxHp = 0;
 			var sumOfHp = 0;
@@ -195,7 +196,7 @@ namespace OpenRA.Mods.RA.AI
 			return (sumOfHp * normalizeByValue) / sumOfMaxHp;
 		}
 
-		protected float RelativePower(List<Actor> own, List<Actor> enemy)
+		protected float RelativePower(IEnumerable<Actor> own, IEnumerable<Actor> enemy)
 		{
 			return RelativeValue(own, enemy, 100, SumOfValues<AttackBase>, (Actor a) =>
 			{
@@ -208,25 +209,25 @@ namespace OpenRA.Mods.RA.AI
 			});
 		}
 
-		protected float RelativeSpeed(List<Actor> own, List<Actor> enemy)
+		protected float RelativeSpeed(IEnumerable<Actor> own, IEnumerable<Actor> enemy)
 		{
 			return RelativeValue(own, enemy, 100, Average<Mobile>, (Actor a) => a.Trait<Mobile>().Info.Speed);
 		}
 
-		protected float RelativeValue(List<Actor> own, List<Actor> enemy, float normalizeByValue, 
-					Func<List<Actor>, Func<Actor, int>, float> relativeFunc, Func<Actor, int> getValue)
+		protected float RelativeValue(IEnumerable<Actor> own, IEnumerable<Actor> enemy, float normalizeByValue, 
+					Func<IEnumerable<Actor>, Func<Actor, int>, float> relativeFunc, Func<Actor, int> getValue)
 		{
-			if (enemy.Count == 0)
+			if (!enemy.Any())
 				return 999.0f;
 
-			if (own.Count == 0)
+			if (!own.Any())
 				return 0.0f;
 
 			var relative = (relativeFunc(own, getValue) / relativeFunc(enemy, getValue)) * normalizeByValue;
 			return relative.Clamp(0.0f, 999.0f);
 		}
 
-		protected float SumOfValues<Trait>(List<Actor> actors, Func<Actor, int> getValue)
+		protected float SumOfValues<Trait>(IEnumerable<Actor> actors, Func<Actor, int> getValue)
 		{
 			var sum = 0;
 			foreach (var a in actors)
@@ -236,7 +237,7 @@ namespace OpenRA.Mods.RA.AI
 			return sum;
 		}
 
-		protected float Average<Trait>(List<Actor> actors, Func<Actor, int> getValue)
+		protected float Average<Trait>(IEnumerable<Actor> actors, Func<Actor, int> getValue)
 		{
 			var sum = 0;
 			var countActors = 0;
diff --git a/OpenRA.Mods.RA/AI/States/AirStates.cs b/OpenRA.Mods.RA/AI/States/AirStates.cs
index e27dcebe52..99fa2bbb00 100644
--- a/OpenRA.Mods.RA/AI/States/AirStates.cs
+++ b/OpenRA.Mods.RA/AI/States/AirStates.cs
@@ -19,7 +19,7 @@ namespace OpenRA.Mods.RA.AI
 	{
 		protected const int missileUnitsMultiplier = 3;
 
-		protected static int CountAntiAirUnits(List<Actor> units)
+		protected static int CountAntiAirUnits(IEnumerable<Actor> units)
 		{
 			int missileUnitsCount = 0;
 			foreach (var unit in units)
@@ -43,7 +43,7 @@ namespace OpenRA.Mods.RA.AI
 			return base.MayBeFlee(owner, (enemyAroundUnit) =>
 			{
 				int missileUnitsCount = 0;
-				if (enemyAroundUnit.Count > 0)
+				if (enemyAroundUnit.Any())
 					missileUnitsCount = CountAntiAirUnits(enemyAroundUnit);
 
 				if (missileUnitsCount * missileUnitsMultiplier > owner.units.Count)
diff --git a/OpenRA.Mods.RA/AI/States/StateBase.cs b/OpenRA.Mods.RA/AI/States/StateBase.cs
index d6c51c91f8..4f4ebda24e 100644
--- a/OpenRA.Mods.RA/AI/States/StateBase.cs
+++ b/OpenRA.Mods.RA/AI/States/StateBase.cs
@@ -92,7 +92,7 @@ namespace OpenRA.Mods.RA.AI
 			return false;
 		}
 
-		protected virtual bool MayBeFlee(Squad squad, Func<List<Actor>, bool> flee)
+		protected virtual bool MayBeFlee(Squad squad, Func<IEnumerable<Actor>, bool> flee)
 		{
 			if (!squad.IsValid)
 				return false;
@@ -107,7 +107,7 @@ namespace OpenRA.Mods.RA.AI
 			if (!enemyAroundUnit.Any())
 				return false;
 
-			return flee(enemyAroundUnit.ToList());
+			return flee(enemyAroundUnit);
 		}
 	}
 }