Also, if you really want to have a ship capable of multiple ship captures in a combat it is possible. I made a Borg mod that does this quite nicely.
The key is adding the armor regeneration ability to the boarding parties and having another component that also regenerates. The Borg have regenerating assimilation drones (boarding parties), neural links (master computers), and armor all to simulate their ability to adapt, keep throwing drones at people, etc. All components regenerate at varying levels (5 for the link and drones, more for the armor).
So long as you have a secondary regen component that isn't destroyed with the boarding parties they will reappear and be ready for another capture attempt. It's quite normal to have one cube capture several ships in a single combat. Which is as it should be.