I apologise in advance if this has been addressed already, but I have noticed that during ground battles, it appears as if the units do not have a limit on how many appear on screen, resulting in significant lag which results in them being a mess of images flashing. 

I have noticed this problem appears in large armies (the issue I had was when I went with about five thousand soldiers to invade a system). 

Perhaps a limit on how many soldiers can appear on screen on any given time? and have reinforcemets "show up" running from behind every round if your troops exceed the number of soldiers you can have on screen at all time?