I had an idea on a change to the actual "capture the base" style of gameplay, but I never finished my idea in my head so don't think I ever posted, but basically it was similar to...
Bring back the "mini" strats, but do not remove the large one. Make the mini-strats capturable. Those mini-strats are tied to 3-4 bases in their close proximity, and have VH capabilities spawning to the surrounding Air-Bases, and 4 radar towers. Make the Mini-strats resupply an item every run (for instance, first rebuilding a few town buildings, then rebuilding hangars, then ack), and make the runs pretty close together, like 5 minutes. However, the strats only supply bases that are the same country as the strat itself. Since a strat would be somewhat "central" to multiple bases, it means a team would either have to fly behind enemy airfields to hit the strat first, or decide to try to take an airfield that is getting resupplied and rebuilt pretty quickly. It also would make some ground targets (strats) a different importance than others (airfields).
There was more to the concept, but as I said, I don't believe I finished fleshing it out enough to post it.