the way i see it, is that they could keep stamina even having auto attack, auto attack would be for normal damage and TP generation, stamina for abbilities of your class and TP for weapon skills of your weapon, i dont think theres gonna be any trouble at all doing that,

as an archer i like the system as it is because i can choose wich action i want to do everytime, i dont find the system spamming, in the other hand with a close melee class like gladiator you end up spaming same action a few times making it a little anoying,

making it short the system works for a few classes and not for others, i would aprove any change but keeping stamina, the auto attack feature would help weapons to be really different from each other like an elm velocity bow being faster than an ash longbow, but having the second one more range, i dont know feel free to add ideas.