I agree it's a good plan; one which will give you a solid foundation from which to go after a GL. I think Rebels will become your third fleet, however. Having done the requirements for GAS, which I assume will involve using Endurance since you're going after Malevolence first, you'll pretty much have a GR fleet ready to go. Admittedly, Endurance isn't great, but if you relic the GR pilots inherent in the Padme and GAS squads, they'll be quite sufficient for a second fleet.
Having said that, if you're willing to put in the effort to gear up all those rebel crew members, they would be more effective than an Endurance GR fleet. It will just take quite a bit of time and resources; delaying whatever your next project would be. You'll have to decide what's more fun for you at that point.