That's hard for me to say as to whether or not the learning curve is easier. Half the obj is accomplished by keyboard clicks, if you use +kb setups, which don't deffer in execution when switching from mouse to tablet.
It's hard to articulate but some experience even if under one peripheral can somewhat translate to using a a different peripheral, I would think. I'd like to hear experiences from people who started on a tablet and didn't use a mouse on how hard it was for them.
I'd say mouse is hard on your wrist and also your, thumb, pinky, and ring finger depending on how much you claw grip. Also tiring up your arm if use a low sensitivity.
Pen is a killer of fingers if you heavily claw grip. Wrist hurts on full proportions when you try to move your wrist as to not have to move your arm.
Can't say definitively yet.