Since we're talking about classic animators, here's another blog identifying and discussing specific animators in classic cartoons.
I will introduce this in a completely off topic way with one of my favorite pieces of animation ever ... Preston Blair's Red singing "Oh Wolfie" in Swing Shift Cinderella (later reused in Little Rural Riding Hood) ... Blair breaks this down a bit in his book, but it's sexy and staggeringly well done and we all love it, so here it is as a starter.
http://classicanimation.blogspot.com/2006/03/preston-blair-swing-shift-cinderella.html