It's a very poor idea. You will have large linkshells (mainly japaneese) over taing control of them and having seekign parties after use time. Or large groups of RMT's controlling them.

It will end up to controlled. It will also result in tension with linkshells, the person gettign last hit controls for the group, setting summon time.

Drops need to be very low in rate in this case, and No tradable/sellable as well if said HNM is defated with a summon.