I know it sounds crazy but why wouldn't you want co-op on TTW?
Just imagine: your playing at home and a friend comes over, well he's interested in playing but he can't so now you have to play a splitscreen game like Modern Warfare *shiver*. Or the alternative is we can press pause, set it to co-op and let him take over one of your followers.
I believe that this would add an extra dimension to this game, how so you ask? Well you have a second opinion to your moral compass. I know that when I play a new game, I can't help myself from doing the right thing, but say my buddy comes over and says why not enslave big town's red for profit?
Now, I am not a modder, I am a tester and an idea pusher, I have no idea if this is even possible, but I don't think anyone has tried.
Thanks For Listening Children.