as a1m3v says they were only replaced by full robots on Earth when the Condesce lost access to the mother grub, so that implies they really are 'troll drones' in a biological sense and probably did exist on Beforus. very interesting to wonder what role they played there though! maybe it was limited to just the genetic material gathering stuff without any of the eugenics enforcement stuff.

I never felt it was indicated lusii were all the same species, so I'd be curious to hear your reasoning for that?

I certainly think that the matching blood colours and scents is a clever trick trolls use to trick lusii into picking them up, though the relationship doesn't seem quite as parasitic as we see in cuckoos: the troll takes the lusus up out