Don’t know much about the technical aspect of tents tbh but I’m going to question your logic here. You’re talking about rain vaporising & seeping in through the flysheet that way. Is that really a “thing”? Do you not want the flysheet to be permeable to vapour so that condensation from the inside can pass through/evaporate? Surely the permeability couldn’t be one-way?
Sure it’s not condensation from the inside? In my limited experience it’s tents being set up badly that causes condensation on the inside, especially when it’s humid (like in a rainstorm!) as it’s more difficult for the condensation to evaporate.
I have a Vango F10 Xenon with a HH of 3000mm, been out in heavy rain & winds and it’s kept dry as a bone inside. IME keeping the flysheet taut & separated from the inner is most of the battle, getting good airflow is important but that’s unlikely to be a problem in high winds!
I’ve seen it mentioned a few times that the HH figure is “just a number” used to sell tents and that there are more important factors like materials used, construction (quality of seems etc) and as mentioned pitching technique, etc when it comes to waterproof-ness.
Anyway my recommendation would be whatever fits the bill in the F10 range as I’ve got 2, they’re the only “proper” tents I’ve ever owned/used and they’ve both been great 😃