Say what you will but, the 320s were bought by RJET after the transaction.
I don't know if you actually believe that multiple lists = whipsaw. If so, you are missing the enormous downside to a joint CBA for FAPA pilots. Single carrier status does nothing to prevent whipsaw. It actually sets the stage for the cheapest way for RJET *to whipsaw* us against one another. It just works out better for you.
How big a carrot do you think WH would need to dangle in front of the IBT EMB pilots to get 51% of the combined list to undo the QOL we've created over 15+ years at Frontier? IBT leadership's setting of expectations for your next contract has been non-existent at best. You think you are going to get Frontier / JetBlue 190 rates and work rules? From the starting point of your current CBA do you think you are going to get anything other than a POS regional contract? With IBT 357 negotiating against RJET? Not likely.
Keeping the work groups and contracts separate may leave a chance for whipsaw on the table, but single carrier and representation by this "Lord of the Flys" RAH IBT group assures that it will be done - to Frontier pilots by RAH IBT pilots. The only bright spot is that you can't vote away any protections (fences) established by the arbitrator in the SLI.