So, I would say the system is in place and does work, but the level of cooperation needed to make an effective attack, makes it pretty much impractical.
Then it doesn't really work if it's 10x easier just to steamroller a base into submission. I can't recall ever noticing an impact on my gameplay from the strat system -- not that some factor might have been reduced to some minor degree had I checked.
My thoughts (among many that have been developed aimed at a similar goal) involve a system where you would have to eliminate a zone strat target to capture a base. Super fast rebuild times, etc. at the fields without having that strat target down. Normal or even increased rebuild times at a specific field (or no rebuild even) after that. A rebuild time of 1 hour or so on the strat target itself. The strat targets because of distance, size and/or defense with super heavy low alt ack would require strategic bombardment to destroy.
Once the strat is down the base could be captured in the normal swarming/cap manner. But, you could make base resupply (barges/truck/rail) more active (volume) once the strat target is down. You would have to dedicate resources to keep them in check as part of the mission/campaign.
What I belive this would accomplish is:
1. A role for dedicated bomber types and dedicated LW interceptor types that has a solid, critical impact on the war. There would always be the need to hit a strat target in any given zone, and a need to defend the target with a greater chance of actually having targets to shoot at. Escort types would also find plenty of action. High altitude fighters could shine in their element.
2. A dilution effect. The action will get spread out as resources are spent on the strategic campaign, resources are spent interdicting more crucial supply targets (all that strategic work down the drain for that airfield if the convoy gets through) and multiple field attacks as the standard jabo types work to maximize the window of opportunity while the strat target is down. You could even make taking a big airfield a GV only process to give the tank drivers a role.
By dilution, I mean sizeable groups doing specific tasks, not rarity of action. Nobody likes to be on the receiving end of a 10 v 1, and some of us don't much like to be on the giving end in that type of fight either. I would guess (only a guess) there would be more fights with better odds and fairly good numbers in each.
3. A strat challenge. Taking airfields would be hard, resistance would be easier, lone milkrunning would be difficult, a reset may only happen 1/2 as quickly (if that) and would require (as mandatory) some level of organization and execution but provide some real sense of accomplishment too. I'm a furballer, and generally always have been in these types of A2A MMOL games back to SVGA AW (FWIW I did far more attack combat when there was only the "central neutrals" and taking a base got you the reward of being closer to the action for A2A). But... I can easily put in pasty skin, marriage threatening hours at a game like Civ. 3. Back in the day I played Interstel's Empire for 18 hours straight before without even knowing most of a day had passed. I can see having some actual interest in the AH strat component if it wasn't just steamroller tic-tac-toe.
Other approaches such as a "shifting front" or a war won by point accumulation etc. offer some valid alternatives to field capture (and may be superior from a strat model standpoint), but might be too radical a change or require too much reworking, IMO.
Charon
[edit: Now for this, you might just need to have "generic" strat targets. They can still be a refinery or factory or whatever in appearance but the impact would be universal on all field attributes: Fuel/hangers, etc. If you had to hit multiple strat targets in a zone it might be too hard, unless the rebuild times for each were such that you could get all of them down and still take a handful of bases before the first attacked came back up]
