Looking at the stages where Vingegaard made a difference against Pogi, I don't buy into the long stage theory. The stages where Vingegaard took time against Pogi have all been rather short.
I know that one day races and GT stages are not really good to compare, but the fact is that Pogacar has plenty of 200k+ wins, including GT stages and including e.g. stage 15 of this years Giro d'Italia, which was 222km long and finished at 2400m altitude. Which is not to say that short or shorter stages don't suit him.
But Vingegaad has one win over 200k in his carreer (Wednesday), and took all his time on Pogacar on shorter stages. So at least superficially it looks the other way around. Pogacar is a natural at long distances, Vingegaard we don't know yet, but it's not improbable he is.