A bad combat system will definitely ruin the game, no doubt about it. I can see the potential there but it requires a lot of work.
However the combat system is not directly tied to quest and general system design. At least I cannot recall a single instance where that would be a problem. As long as they don't introduce additional starting and ending states, they can replace it with any variation if it. By adding a state i mean shit like bleeding. Bleeding would mean that somebody can die after combat ended. No G1 quest is ready for that. All quests depending on the G1 3-end-state combat (undefeated -> defeated -> dead) would have to be redesigned.
However the combat system is not directly tied to quest and general system design. At least I cannot recall a single instance where that would be a problem. As long as they don't introduce additional starting and ending states, they can replace it with any variation if it. By adding a state i mean shit like bleeding. Bleeding would mean that somebody can die after combat ended. No G1 quest is ready for that. All quests depending on the G1 3-end-state combat (undefeated -> defeated -> dead) would have to be redesigned.