Analyzing openings from chess variants

Is there some way to know if several opening lines from chess variants (Namely Crazyhouse, Antichess, Horde, Racing Kings) are/were analyzed properly? If not, I believe we could simply start it here.

For starters, why exactly the antichess line 1.e3 b5 2.Bxb5 Bb7?! is said to be good for white; while the crazyhouse line 1.e4 Nf6 2.e5 d5/Nc6!? is good for black?

A lot of good players have they own study)
also we already have RK study with 52 chapters