Problem I see there is whether Delta would ever be willing to pay the equivalent rates pilots would probably demand. Endeavor pilots, while well paid, still operate at far less pay while supporting Delta’s operation and filling those connecting hub seats.

A way I’ve tried to do a comparison is looking at the closest equivalent aircraft at Delta (the 717) to Endeavor’s largest fleet type (CRJ-900) to try to imagine what it looks like to the bean counters.

Delta 717 Hourly Rate in terms of per seat on the aircraft:
3 Year FO: $1.35/seat
5 Year CA: $2.20/seat

Endeavor CRJ-900 Hourly Rate in terms of per seat on the aircraft:
3 Year FO: $0.84/seat
5 Year CA: $1.32/seat

So a Delta captain makes equivalently 67% more per seat compared to an Endeavor captain, not to mention the vast difference in retirement contribution, per diem (29% more at Delta), profit sharing (none at Endeavor) and other benefits.