Assuming a Tyranid Hive fleet, or part of one attacked a planet ruled by one of the Chaos Powers, but that the hive fleet was defeated in space with only part of its ground forces deployed, do you think it would be viable given that the hive mind link was broken for the remaining gaunts and other non-synapse creatures to be tainted by chaos?

I am assuming that they would, unless killed in battle or whatever, survive in a similar manner to other apparently 'nid related creatures such as the Catachan Devil and that old Carniflex, what was his name, old one eye, or whatever.

Given that they had no link to the hive mind would a chaos sorcerer or pysker or even a daemon prince be able to bend them to the cause, creating things like plague biovores, or khornite gaunts and the like. Perhaps even a Soul Grinder with the body of a Hive Tyrant or something. (I assume even a Hive Tyrant cut off from the Hive Mind for any lenght of time would become suseptable.)