change it to ferals(they were put into some roleplays in Unit-13. drugaddicts gone extremely wild and violent, pretty much rabid even)
I was about to say "clones", but I guess your idea is even better.
Concerning Zombies using SMART, I would actually say that Zombies do act quite intelligent when trying to reach some fresh meat. However, they would require more zombie-alike SMART-animations.
And finally: Zombie-idea ... doesn't seem very random to me. More like .... common. If you run out of ideas, play the "Zombie-Mode Card".