From: Decatur, GA, USA
You will get two different sets of Banshees. If you use the first set, those squadrons will get to be at low strength with good pilots. If you then rush your second set of Banshee squadrons to the theater you can disband (no reform) some or all of the first squadrons into the second set without costing PP's although you will lose the PP's for early withdrawals.
I wouldn't be surprised if this was historical - that some of these early squadrons were merged into reinforcement squadrons IRL
I don't remember all the details of which P-40 and Banshee squadrons you can save the planes through "disbanding" into another squadron - some you can, some of the P-40s you can't. But unless its been changed in the latest version, I'm pretty sure you can save most or all of your Banshees and, at the same time, put their experienced pilots right where you need them without delay. Some of the far eastern P-40 squadrons, I know, won't let you save the planes through disbanding. Under the new system, you can always save pilots through transfers, however. Of course, you know the program lets you know whether planes will be destroyed on a disband before you have to go through with it.
If you can save the Banshee planes when you get to this stage, I doubt you'll want to spend PP's to keep the first set of Banshee squadrons around since you'll be able to productively use up all the planes in the second set of squadrons.