So, suggestion is really simple and not game breaking. If you check dynamic alliances, you can as well specify alliance limit, with default to unlimited. Say, you can set it to one, meaning you can have only one ally at a time. This should create some really cool diplomacy experience, especially with alliance victory, where you have to be careful about friends you choose. I.e. you can ally with your closest neighbor, and then get alliance request from a really powerful commander. Should you accept and start imminent war with guy you are literally 5 meters apart? Or should you deny it and possibly die with your ally in a few minutes? Also, this will solve problem where one guy just allies with everyone and stockpiles army while all the other players annihilate each other, at the same time having full intel about everyone. Yes, well, not 1.0 but it should be in at some point. More gameplay variety, and the cost is one simple "IF AllyCount >= n, NoMoreAlliesForU = TRUE", Accept button grayed out, non-ally check boxes disabled, etc. Yeah, maybe not that simple, but it shouldn't be hard, right?
What i was thinking is if Allied Victory is on, to prevent all but one army from teaming up and crushing the latter, perhaps the game would only end if at least half of the players are dead? so in a 1v1v1, at least 2 guys would have to die in a 1v1v1v1v1 at least 3 would have to die, etc. This is essentially the same thing, but it makes sure there is a limit. just not in live time.
While they are at it, implementing an alliance for Team Armies would be awesome. Having the max alliance would be less important here, but in a 2v2v2v2v2, it could be useful. I like your idea, ef32.