Heavyweights do not have magically strong chins just because they are heavyweights. A puch that can KO a Cruiser is just as capable of doing the same to a heavyweight. The only difference lies in the fact that to deliver the punch, you have to reach further and higher, that may be the difference.

Haye will not unify. He may get past one or the other, but the odds on him beating the Wlad and Vitali back to back are slim.

After the Barrett fight we will get an idea of how he may fair. Considering how poor Peter looked, he may actually be the only person that can beat either, but that as of yet is unsubstantiated. The fact remains, the heavies are screwed because nobody else will trouble the Klitschkos and they will never fight each other.