My experience has been that while one or two guys can get to the strats because folks just don't bother to intercept, but if you have 8+ guys they do.
I do fully agree... 8 formations make a good darbar and will attract a lot of attention. If they are the usual B-24/Lancaster formations, they are very likely to get shot out of the sky.
But there is no need for 8 guys. With B-29's, two players can wreck the city, while a third can kill one or more factories (Or the two city killers can come back for the factory, after all City stays down for 6 hours) And they do not have to go in all at once, flying in the same sector all the time.
On a map like Ozkansas you can pretty much blend in the background noise of the very close frontlines. I once did it during an afternoon with one other player (later some other players attacked the strats independently from us), and it took the enemy ages to notice what was going on, and then the response was never a strong one.
You'd be surprised how hard it is to get buff drivers to escort
No, I'm not surprised at all

Overall (and this is a general note, not directed any anyone specific), the mindset, awareness, knowledge and creativity/planning of the AH player population is rather ... limited, both in attack as well as in defense. I know this statement smacks of arrogance, but that's how I do experience AH

I also remember, when we had smashed the City on Ozkansas and started to take down factories, we tried to get some more buff drivers to support us, to no avail. Most were seemingly unable to
understand what we were trying to do, as a matter of fact, several players did simply not believe what I was saying about the supply mechanisms. But worse: Even the well known arm chair generals who usually cry for porking of the enemy were listening to us when we pointed out that if they would pork the enemy frontline ords NOW, they would stay down for a much longer time than usual.