Yes, one of the rules for the Games Versus is that characters must originate from a video game and not some other medium. If we didn't have that, there would be match-ups with characters from another mediums (in this case, the Borg) with a large amount of material to draw feats from coming against comparatively unknown video game characters with little to no feats to draw comparison from. Helps to avoid a lot of a spite threads.
__________________ -"My internet is currently so bad I'm time traveling. Don't worry about it."
-"You have the best problems, Scenario. You really do. haermm"
Oh, I see how it is. Everyone wants to have some fun at ol TacDavey's expense instead of debating the topic, huh? And it's a good match up too! Admit it! ADMIT IT!
They [try to] assimilate any species that can add something of benefit to the collective. Can't recall if they've ever assimilated a synthetic (tried with Data, did his body, but his positronic brain proved too much), but they've assimilated a species composed of pure energy before.
The Geth don't run on anything like positrons, I don't think, but they might have some issues converting the collective to their cause. The Reapers, Ancient synthetic psuedo-gods from the Mass Effect universe, were only successful in converting a portion of the Geth to their cause...at least, in one player choice path, though I believe that is the canon result.
__________________ -"My internet is currently so bad I'm time traveling. Don't worry about it."
-"You have the best problems, Scenario. You really do. haermm"
Wasn't that because the signal couldn't make it to the others for some reason or another? I thought I remember Legion saying something about that.
The Borg have transporter tech that the Geth don't, though they can kind of shoot themselves down to planets and stuff.
Also, can the Borg breath in space? I seem to remember them being vented out into space as a way of killing the Borg but I can't quite remember. If that's the case, I suppose the Geth could vent the ships if they ever have Borg transport over.