That's outside of the point. A third button for extra commands and moves just adds more depth.
I don't think you got my point.
More buttons doesn't neccessarily correlate to extra commands/moves.
Street Fighter is a 6 button fighter. Tekken is a 4 button fighter. Which one has more moves? Tekken by a landslide.
Likewise despite PSASBR being 3 attack buttons and Smash 2, they actually have around the same amount of moves on average. Again, it's just mapped differently. PSASBR could have had the same amount of moves it does now with 2 buttons if it wanted.