First of all, I would not argue that the Japanese are expertises in designing of such complicated toys in the world.
However, everyone knows the DX series is a BIG project. How would Bandai simply pass such an important project to an inexperienced/ incompetent team? That is not sensible to me.
My view would be that some Chinese designers are involved, to let them gain some experience or wise. But if someone said "it looks bad because it's designed by a Chinese design team", it looks more like shifting the blame.
For "durability vs accuracy", I understand that some accuracy is sacrificed for durability, but IMHO there's much room to improve the accuracy without hurting the durability.