When to swap mosaic

I am playing ssf on console and decided I want to make a mosaic assassin. Would I be good to trap through nightmare and then swap to mosaic build when I get to hell? The only issue I see with beating hell might be ancients just because of keeping the charges up.

I plan to level enough to use my wmenigma, shako, cta and dual mosaics at the start of hell. Should this work?