Every time I see an animated movie with a big crowd scene I feel for the crowd animators - talk about an under-appreciated job! But what you say is definitely true for both crowd scenes as well as one-on-ones. Or even single shots with moving background elements... even the wind in the trees in the BG can be distracting if it's out of context!

This is a fantastic post! I know I'm an animation nerd but keep it up anyway! :)