2. The head guns made me think that these were cyberconverted Silurians. Which doesn't track easily since the Silurians claim to have been hiding from a rouge moon we would one day call luna but the ELE meteor which killed the dinosaurs was a time travelling frieghter loaded with cybermen and cybertechnology... But they could have "met" any old time.
Good point, in all the years of pondering how the Borg were so much like the Cybermen, I never thought about the Cybermen "assimilating" other races.
The story itself is a bit rubbish, but I like the Cybermen of old and Ms Sladen, so I watched it all the way through last time it aired.