Both those points would generally have Caches placed on them though, surely? I'd have thought that would provide enough of a buffer to allow you to react and prevent a massive cutoff manoeuvre from succeeding, though I haven't really seen it all in action.
I haven't actually tested it; Does the Stuka Divebomb both destroy a cache and decap the point underneath unsupported?
Well, both of those maps happen to have buildings nearby to spawn stormtroopers from. If no one notices them coming out then you can hide them to wait for the schreck upgrade. The schreck + flame nade destroys a chache fairly quickly (90 muni, ~14 secs). A flame nade + the mp40s firing can be enough too (30 muni, ~23 secs), tho this gives them a longer opportunity to react.
You can also use the storm's smoke nade to keep them on the cut off points as long as possible,for the longest ctp active time (max 45 secs).
As for the stuka bombing it can only damage a chache but can't destroy it at full health, it does like 1/5 damage to it. However there were cases when the chache was so damaged, that the stuka both took it and neutralized the point (and iirc those are also the times when ctp tends to act weird, either not activating at all, or even attacking neutral territories).
Fun fact: the actual stuka bombing (200 muni) does 4/5 damage to chaches!
There are plenty of ways to defends against storms, apart from building chaches. Destroying or wiring off the buildings they can spawn from is one of them. Storms also hate mines cuz they can't see them, this can also help against vehicles diving in with breakthrough. USF can build firing positions to look over cut off points. Another good strategy is that if you deploy a AA HT against planes, then put it next to a cut off point, generally it can still do its job while also protecting the point.
There are two other ways which I think can be effective, but haven't seen being used. One of them is putting a scout vehicle around the cut off points (M3, M20, UC), I mean they are generally cheap and have a low population value and they can detect storms from a fair distance away.
Another way that may work is deploying a vet3 major (it's not hard to get them to vet3, just bring them along with your combat units), they can completely prevent a point from being captured, not even the stuka can neutralize it (just tested, it's ridiculous)!