Just a thought, but why not have players added to an array on join, and removed on disconnect. Then do the same for bots on spawn/destroyed. That way, you only have to interate through the list for whatever you are trying to do, not build the list and THEN do whatever you have to do. If you are really worried about missing something, set up a timer (like once a second) that polls the Get All Actors of Type and checks the arrays.