根据已经创建好的僵尸，又复制多十几只出来，运行游戏发现太卡了

Characters array resized. For best performance increase the size of the Start Character Count variable within the Deterministic Object Manager to a value of at least 18
UnityEngine.Debug:LogWarning(Object)
Opsive.UltimateCharacterController.Game.DeterministicObjectManager:RegisterCharacterInternal(UltimateCharacterLocomotion) (at Assets/Opsive/UltimateCharacterController/Scripts/Game/DeterministicObjectManager.cs:295)
Opsive.UltimateCharacterController.Game.DeterministicObjectManager:RegisterCharacter(UltimateCharacterLocomotion) (at Assets/Opsive/UltimateCharacterController/Scripts/Game/DeterministicObjectManager.cs:283)
Opsive.UltimateCharacterController.Character.UltimateCharacterLocomotion:OnEnable() (at Assets/Opsive/UltimateCharacterController/Scripts/Character/UltimateCharacterLocomotion.cs:561)

没有报错，只有黄色的提示，我按照提示，将Deterministic Object Manager脚本中的Start Character Count 设置为18了，但是运行游戏还是好卡，又多次将这个值设置为50、100、甚至1000，运行游戏还是好卡，请问老师应该怎么优化性能，让他不卡呢，想设置多点僵尸，打起来才好玩。