Hi rdsarna,
Saw your question and would like to comment,
To draw characters well from your imagination you need a library of reference in your memory.
Studying anatomy only gives you a piece of that library. It’s an excellent discipline to learning how a muscle is shaped and where it attaches. But, characters in animation are often exaggerated with squash and stretch and understanding how far a limb can stretch, how much can it rotate and where that line of correct rotation exists is only theory unless you see it in action on a real person. To know how to animate believably, you should know what the boundaries are.
Someone can explain to you how weight mass is distributed on a human form, but seeing with your own eyes how real forms rest on an axis on top of each other such as a torso over hips over a leg holding a person’s or even an animal’s weight says more than a thousand words could.
Or drawing a body bending over using only theory may come out wooden if you haven’t observed how the torso bends and how much the belly collapses into itself without seeing it on a model first. All this helps to sell your character, especially if it ranges in the more realistic representation. Sometimes what you don’t do well shows more clearly than what you do correctly. Multiplied if it’s on a big screen.
The traditional animators of old definitely knew this and their work was fluid and beautiful even if the characters leaned towards the cartoony. 3D characters are built differently, but the principles of shapes in structure and fluidity in movement are the same.
Hope some of this makes sense.