I think it's a bad matchup for Overeem if the fight stays standing. Volkov throws straight punches in bunches and Overeem doesn't protect his chin well. Overeem would fair better against Derrick Lewis (who only beat Volkov because of his chin/toughness) or his ilk as he just has to watch out for the big wind up haymakers. I think those straight punches will cause him all sorts of problems with the way he holds his hands, etc. That is unless he is able to take him down, which should be his immediate goal. K1 Ubereem takes him out striking but not this less potent striking version of Overeem.