Communication makes your stronger, voice communication with your own team makes you even stronger. Teams playing ladder should fight only other teams, like in any other modern game.
Discord ladder advantage
MMR already takes account of this over time - play in a team regularly and your rating will be higher than someone as skilled as you individually who doesn't play in a team, meaning you get balanced matches.
Also limiting to only teams vs teams (which would mean it'd have to be only teams of the same size against teams of the same size, with other players then added to make up numbers) isn't really feasible with such a small playerbase
M27AI developer; Devlog and more general AI development guide:
I should get better teammates when I'm in voice with friends because talking while playing reduces my iq from chimp to sloth.
Yeah, I also play worse when I have to talk to people. Playing with a team is kinda the point of team games isn't it? I don't really understand what drives people to play team games alone where they never communicate and don't even look at what's happening on the other side of the map until an ACU explodes. Just like playing a 1v1 with extra lag and misery added at that point. Hence, I only play 1v1. Clearly I'm in the minority on this though so I'm probably insane, or everyone else is.