...unless of course you're a Tholian.
As far as the Breen raid on SF goes, it only occurred to me during the writing of my little rant, so I wasn't basing anything on that particular event, I just realised they happened to support my supposition.
Okee doke. I didn't want to put my foot in my mouth trying to debate something I never even saw
When it comes to the range and refuelling cycle of an Attack Fighter, given that it's most likely capable of crossing several light years at warp, I think it's safe to say it's range at impulse without refuelling can be measured in months. So the likelihood of one needing a mid combat recharge is exceedingly slim.
Well for our benefit here we're going to have to assume the fighters are not warp-capable, otherwise there'd be absolutely no point to putting them on a carrier that isn't.

So you gotta gimme a caveat on that one.
If as you say the enemy would first take out the ground bases then again, an aircarrier would be useless as I stated before a base would be much more heavily shielded and far more entrenched than a mobile unit could ever hope to be. Coupled with the fact that if most major cities have such a base then there would be hundreds of them all over the globe and to take out hundreds of heavily shielded ground installations, while dealing with orbital weapons platforms, a home fleet AND defensive fire coming from said surface bases would require a bloody awful lot of fire-power and a sustained barrage from a fleet of near invincible ships.
Actually, there's several problems with that. One of the most immediate ones is that assuming the society in question (and it's probably easiest for us to pretend we're talking about Earth here), then you don't want shield and weaponized fortresses in cities because it makes them valid military targets in an environment populated by civilians. We see it in the modern age with missile platforms next to hospitals.
Secondly, all fortresses can be breached. If we use the Breen example, the easiest thing to do would be to not target the city but the faultline instead. You could undermine a facility with phasers or torpedoes if your'e so-inclined, even if the shields could take the impacts directly. Really, there's no end to the options.
The problem with a stationary target is that it's stationary. It can't adapt. Once a half decent plan to breach it is developed, it's like a drunken teen on prom night. Thousands of years of warfare have taught us that once they're inside your walls, you're borked.
So if they can handle all that, what bloody good would a bunch of "helicarriers" be, even if they are tricky to target?
A moving target is harder to hit. And I'm not talking about from the weapons-tracking standpoint. It's harder to plan for, it's harder to reach and it can adapt to changing conditions.
Also there's the small point that said barrage would probably devastate everywhere between the cities that aren't shielded and you have yourself a poisoned well scenario again. Which of course may be the point since the best defence is to make attacking at all too costly for the enemy to bother.
The problem is that on the galactic scale, the poisoned well defence is not that much of a plus. If they intend to occupy you, then it can be. If they merely intend conquest, it's not - because if they wipe out your planet, you're going to lose a lot more than they will. Lots more fish in the sea.
If they do intend to occupy the planet and antimatter weapons aren't an option, then you've radically multiplied the capabilities of the local defence structure.
That rambles a bit, but I hope it makes sense.
