Thanks for the extensive feedback,
I don't know if we'll work further on the game, what is plausible is that we reuse the same system in another game, in which case with more time we'd definitely add an alternative mouse control with tool-tips, and then we would retroactively implement it in this game too.
Not certain we will though', the thing is that for bigger games I prefer bigger parties, and what I liked here with picking 3 among 4 is that every single combination (of 2 and 3) can have its own unique action, if you get to pick 7 among 12 or whatever (with also the possibility to use the same class more than once) it becomes impossible to fit every possible combination with a totally unique action so the purpose is a bit lost, it's not as cool.