Seems to me this whole fiasco would be made easier if the faa just put out a bid that was tdy to n90 for training/until they get the number of people needed to work the area from phl, once they have that the controllers start working in phl, along with any ewr area controllers who want to move. Thr n90 guys that don't want to move train thier replacements and move to a different area, ewr goes to phl and its done.
Just make the bid explicitly say "you are on the phl books, training at n90 till xxx date or yyy number of people are certifed, then you go to phl" Everything is voluntary as far as moves and work assignments outside of the ewr controllers retraining in a different area, but they don't have to leave thier established lives on LI even for a day, the training and move gets done, and no one is going to long Island with the expectation of staying there and getting established or having to get sucked into a move or tdy work they didn't volunteer for.
I dunno that seems like a solution that benefits the most people and accomplishes what they want with the least amount of pain and financial expenditures.