If squads enabled, limit to 2 people per squad over 10x players, (2 people @ 20total, 3ppl @ 30total, etc.. per team).
What is happening now is people are purposely joining with random names, then joining with their original name to ensure they are on the same team. Same concept. If people are leaving / join (mods included) to make this happen, then it should be adjusted as needed to avoid team stacking.
So at end of day, I think either have squads for 2 people enabled(or formula) or is disallow it overall to keep it fair(regardless of status). People keep leaving and join to stack the teams. (Anybody can exploit this if wanted to, or willing to; it shouldn't be a difference)
There are a few clear cases this as already happened without squads.....