First, this may not be roleplaying, but Necrons working with Eldar breaks any semblance of fluff. Secondly 3 5 man factions doesn't work either, as one man it is an odd number and so one person gets no game, and it makes organizing the challenges very difficult. If we go with my plan, then I'm in the wings to replace the next drop if any, or to fill in for anyone who needs it. Short of anyone else declaring a desire to drop, my plan with probably be what we go with. I'll drop the info on reinforcements latter tonight.