A good chunk of the Calvert stuff is actually on ones if you look. Certainly much of the Tack/Zigzag fight is on ones. I have sped up some stuff in my cut to put it on ones, or used other tricks.
The confetti and the pullback is actually on twos to start with.
A lot of the Williams stuff is on twos if you look too ... only when appropriate though.
It's not clear what actual Williams animation, if any, made it to the final version that wasn't in the Calvert WIP. The London team did a pretty good job finishing some Williams shots.