A'yup, roofing sucks. There ain't nuthin' easy about it.
As far as getting sheets of plywood up onto the roof, if it is just a one story, the cut man can be down below handing the stuff up. That usually goes smoothly enough.
If it is a two story, you're probably better off having the crane that is going to set the trusses pick up a stack of roof sheathing, and stick that inside the exterior walls on the 2nd floor, floor. Then pass the plywood up between trusses.
As far as the subs splitting on you, TAB, I can't say I blame them. Ya gotta go where the money is. Or where you will get taxed less and end up with more money in your pocket.