What is so important about being the Captain?
When I was a new aircraft commander in the Air Force it was defiinitely cool to be the guy making the decisions. 10,000 hours later it matters not what seat I sit in. I imagine many feel the same way. So it probably boils down to pay. So pay a 6 year AT capt (there are none or few) 6 year SWA Capt pay and let him sit in the right seat till he can upgrade. It would be a win for the AT guy as he can hold a line as an FO rather than sitting reserve as a Captain and still be compensated.
Let the 10 year SWA FO upgrade.
Win - Win. SWA can keep good will. Cost of doing business
Wasn't something similair offered to the Frontier guys?