My point is more on the lines of a molecular sized part of Bobby remaining in the arena and Bobby remaining there. We are the ones assuming that if Flash takes a chunk of Bobby his mind will leave too, assuming that the size of the chunk matter.
Iceman has splited before, but he knew it, his consience was there interpreting his position, if Flash actually speed blitzes, it could be that Bobby is left behind instead of taken with the larger chunk.