This is one of the stupidest things I've read. Do you understand that animating battles is not more complicated than character acting? The act of animating character acting, expressions and subtle movements takes just as much and Tenshi is a great example of this.
Of course there will be good and bad from any studio, this doesn't just apply to JC Staff. It depends on the Production Line, Producer and those staff specifically. Index, DanMachi, Tenshi are examples of when they have a good backing and what not going with who's involved.
You should only be looking at Index, and their CG has been guite good for it, better than most anime. Index Movie is a perfect example of that or even the CG AC in the background of the Teaser or even the Index VO Opening.