How's that a hard question to answer. It's not like there's no tape of Lewis fighting. Just watch him fight when he was younger and this question is easily answered.
In Order : Lewis, Vitali, Wlad. I would add as a fan of both Lewis & Vitali, Lewis and Vitali are a toss up. Before you *****, Lewis Ko'd 2 Times, Vitali never Ko'd, yet lost 2 times due to injury. A loss is still a loss for ANYONE! But I think in analyzing any fighter against another fighter you have to break down those losses and how they lost! Again, before you *****, a loss due to to injury in my eyes is better then a KO loss. How do Lewis and Vitali stack up against equal fighters, we will never know as we only have who they both fought against to judge each other by and their fight against each other. Most fans will not judge by a fighters abilities or his record, but will make excuses for a fighter in a certain fight, that is being biased and 99% of the people on ESB are GUILTY of THAT! I could go on about both and who they fought and who they did NOT and why they did NOT! That works for both VITALI AND LEWIS! They both had there ups and downs and if H2H you could have 2 guys share one spot (Impossible) I think it would be Lewis and Vitali. Before you go nuts responding with your biased opinion for a certain fighter. Post your serious responce and I will respond to it with my serious thoughts. Could not make a descion on the poll as I can't put Lewis and Vitali both as my pick. Would be lying if I picked one over the other! Just My Thoughts, Peace!
Fat Lewis already beat prime Vitali by way of facial amputation. Prime Lewis smashes any version of Wlad, he'd be picking bits of Wlad's jaw out of his knuckles years after.
Prime Lewis would KO Wlad and beat Vitali by decison. I have always though Vitali would beat Wlad by KO too. So for me : Lewis, Vitali, Wlad.