As far as I understand, Mumble is an open-source Voip application that is scriptable.
The idea is that one could use this to talk to each other, automatically joining you current Team's channel. Mumble also supports position based technology, so you would only hear people that are close to you. IDK if the last, or even the first one is possible though.
If one could send the players in team-list to a mumble server, one could script the server to sort all those members into group A, and the others to group B.
That is the very basic and simple approach. If one could also extract positioning of players data and send and adapt that to Mumble we could speak to whomever we meet on the field.
The next step is to have a commander election system, where commanders get priority speaker and longer range voice..
I know this sounds very ambitious, but we all know what chadz is like, the bigger the better!
Note that this suggestion comes from someone who has absolutely no idea about programming or how cRPG is made etc.. If this is indeed impossible, then come forth and tell us devs!
Now how would it be to have everyone speaking at the same time? Tiring? Probably. Fun? Probably. RP? maybe. It would change the whole game experience for sure. On NA it would be terrible, people would play back porn sounds and extremely annoying music while fighting. But on EU I think it could be possible.