This deal is gonna be an America West/US Air situation all over again. Fighting and lawsuits will continue for years and years.
I honestly think Midwest and Frontier guys should be mixed by relative seniority and then place the captains at the top of the Captain list and the FOs at the top of the FO list. Put the Midwest guys in the E190s and lock all Frontier and Midwest guys into their aircraft for 5 years.