I come from CGI, or 3D animation (modeling, texturing, rigging, lighting, rendering, etc), so I’m not sure if 2D animation is more difficult or less difficult to deal with. Sometimes something that you might think is easy and basic turns out to be quite a complicated process. Not always, but sometimes.
There is more than one type of animation, and that might require different solution. I believe the term for combining live action footage and animation footage is called “compositing”. I’m not sure about 2D animation (or cut-out/stop-motion, and some others), but with 3D animation, there is often a need for stuff like color-grading, so it’s more complicated than just taking the animation sequence and put it on a live-action background.
Compositing is on the VFX (visual effects) side of things, so it’s more editors than animators, or more specifically (correct me if I’m wrong), compositors. People who use Nuke, or After Effects, are the people I would personally look, and that is regardless to the type of animation.