Well to be honest we already have 3 classes in this game: mc fighter, ua fighter & mixed ua/mc. Within these 3 classes we have sub classes defined mostly by what choice of manouvers you use i.e bloodlust, meditation & death or glory could be seen as the typical offence focused warrior meanwhile something like oak stance & meditation could be seen as more of the defensive focused class and so on.
While this system has a lot of potential its unfortunately being gated by having too few abilities and too many useless moves, im glad that all moves are being looked at in the new combat system.
So how about we have a separate choice of "credos" or whatever and there you could choose 1 of 3 choices: MC, UA or MC & UA. Choosing one of these would then unlock new upgrades for moves within those 3 stats, for example mc could unlock upgrades for available mc based moves, you could have 5/5 points which you spend 1 of to upgrade a move and depending on the move choosen you have static change to the move such deal more damage, deal more opening, use less ip's, etc(you can also respec for free). This has a lot more potential and customization than stupid static classes that force your character into one way and that way only.
Besides that i really like Zente's idea of sliders.