Hi Bryan,
logic level FETs are so closely matched that as long as they're
all the same type to start off with you should be able to just wire them in
parallel. In a 2kW audio amp I have seen this was exactly how it was done.
I can see where you are coming from but you have to remember that FETs have a
negative temperature co-efficient. The hotter they get the higher the on
resistance.
Regards
Nick Field