In the TNG espisdoe descent the rogue borg have long range wrist mounted weapons... that we never see again. Which doesn't seem very "logical," even if the Borg are trying assimilate they could use a stun setting and then inject the nano probes in the unconscious targets. I can see the real reason is that they don't do that it is that it would make them over powered and hard to for the heroes to survive, but I wonder if there is a way to justify it in universe.