This might just be one of the best rotations + background animations in HISTORY

how hard would it be to animate such a scene in comparison to anime and other forms of visual art

It's very difficult yeah. I'm sure a mecha anime animator who's used to doing hard surface stuff could do it too. The animator posted a process video here
https://www.youtube.com/watch?v=sws1AzuLAu4
And I've gotta say, I'm not sure it's worth the bother, as opposed to rotoscoping footage of a carboard model or using 3D