I'd be disappointed to see Maria locked out by route selection, though it makes the most narrative sense for her to seek the most protection from the Warren gang. With everyone out to turn on her, her best gamble is the ones who aren't in the game yet, even if she's just a pawn to them. It would be interesting to how she could be made accessible to other gang routes.
I think Mike's best bet is the Warren gang, even if it means crossing Nesrot, the only reliable partner he's done business with so far. Warren will see Mike as a liability whether he comes on board or not, but it's best to keep your enemies closer. Maybe you could make a truce with Nesrot to bring old man Warren down from the inside, and knock out his rotten grandson, too.