Allow hero switching- but only if the match hasn’t actually started yet. Currently once you’re locked in, that’s it, and if everyone decides to forgo diverse team composition, you have no way of filling the gaps. There’s been many times where, had I known nobody was gonna go tank or support, I would have happily swapped characters. I don’t know if this is actually something they’re able to change or tweak at this point, but during the match countdown I could see the option to reroll help greatly with uneven team comp.
This is not a massive problem by any means, as I myself have had several matches with only assassin’s and damage dealers win, given how this game tends to play a bit fast and loose with roles, but against a well composed and well rounded team it can be a real uphill battle.