Animator pretty much required a mouse or tablet though and it was released late enough (1989) for PC mice to be common and certainly something someone would buy to use software like that. There is support for moving the mouse pointer using the arrow keys, but I can't imagine many were drawing much like that.

Keyboard overlays were probably even more common in the 1980's. The F-keys make a lot more sense when there is an overlay for the application you use. Memorizing what each Fn is for is no fun unless each key somehow map to something related to the number n.