It's the heavyweight division man any heavyweight who gets tagged by a big puncher is going to have trouble... the key it to avoid that by utilizing your other skills sticking your chin out and getting tagged doesn't make you a champ...
Maybe David Haye if he improves a lot. IMO Wlad can only lose to a skillful big puncher who also has skills and the energy to swarm him. There is no one in the heavyweight division like that at the moment, Haye maybe in the future.
Haye doesn't have the chin to get inside and land his own big punches... One other name I forgot who might be able to get there if he improves his skill is Virchis. He has a hammer, and if he can walk through Wlad's offense to tag his chin, he might have a shot.
If just going right at him were that easy, Brewster would have done it. Fact is, he's very aware that fighters want to get inside and go to work on him, so he is very carefully to prevent that, by keeping that jackhammer jab in their face, and also that straight right banging their head back. Just going right at him is not really a good plan, anymore, cause he's aware of and ready for that, now, as he proved in a few recent fights. But that said, just going right at him is still the only hope, even if it is a slim hope.
Povetkin, Dimitrenko, Chagaev are all threats in a 5 year span. Peter is vastly overrated. As soon as a referee starts calling him for illegal blows he will not have much of an arsenal, and his defense sucks. A timid, unconfident Wladimir schooled Peter for 35 out of 36 minutes. Today's Wlad, with rediscovered confidence and a better defense borne of Manny Steward's tutelage, TKO's the slow and lumbering Peter in 8 rounds or so.