Skin tone really isn't an issue there are plenty of images with everybody all done up so you could totally do the main 6 with only one male and one female chest block .They could easily do a box set with Chamber (with what ever fire blast add ons they care to make to give him an alternate look), Synch with a skin head arms and legs, M with a Husk head piece and Jubilee and if they really wanted to be generous throw in an extra set of the red arms and a Gaea head. They would have a box set that everybody would buy two of with out much in the way of new tooling. As for whose dead and inactive and whatnot I don't think it would be much of an issue because it would be a specialist market thing anyway.