Honestly, I think if they allowed 6 character party and implemented the 5e rules more accurately, that would balance the game out very well. That means enemy stats more true to 5e as well.

I've been testing as Tabletop, and I think the enemies they throw at the player(s) fit better with 6 characters IF 5e rules applied. 4 characters sets the difficulty to Hard if 5e rules are applied.