[reverseblade2]

- Yes, pcs don’t have to share the same columns.

- There is a certain level uncertainty about where these pcs will land. Yes perhaps stockfish could try to add all possible future placements but I expect that would significantly hinder stockfish as the the number of possibilities grow hundreds of times.

Your opponent doesn’t know which piece will be where until you reveal it. Therefore can’t attack a non defended pawn on b column because you may reveal a castle on next turn.

On the overall it mitigates problems of weird openings in regular chess 960 but End game stays the same.