And nah, I don't think any of them have means of countering country- island level ap.
Yeah I think that too, yes they are op but as compare this was done by Melidoas who was weaker then Escanor:
That feat was crazy, yet Escanor even do something better and vapo a whole lake in some seconds.
And Durability wise he easily no sell this attack:
The question is rather, can Vanica curse him via her own magic?
In that case it would come up who had the better magic power, is Vanica magic power strong enough to curse someone as Escanor who hold himself a Holy magic power? Can Zeno even pierce him down or can Dante graviity put him down. I really don´t know if they could doo that against Escanor...