Are Wlad's and Vitali's fighting styles really that different?

Completely different fighters. Whoa! Too many details!

They're only similar in the fact that they're heavy handed in both hands. As UKR ALEX pointed out, their technique is way different and obviously evident if you've watched them fight before. I do realize that Vitali does a LOT of simply leaning back to avoid punches, but I think he's actually a little more fleet of foot than he's given credit for, and even similar to Wlad in that respect. Think about it for a second and you'll see what I'm getting at. None of us here on this board (certainly not me) are champion heavyweights, and even we know that if we can see that a fighter evades punches by simply leaning back, logic would dictate that all you should have to do is throw two or three more punches coming forward, theoretically causing him to lean further and further back. Certainly if WE can think of this, a professional boxer could, and of course they have, and they HAVE attempted it. To no success. So how can this be? Simple, he's more fleet of foot than we think. Another similarity to Wlad, but not one that's as glaring as the others.

Completely different fighters.

They're only similar in the fact that they're heavy handed in both hands. As UKR ALEX pointed out, their technique is way different and obviously evident if you've watched them fight before.

I'd say their styles are very similar...and by style I mean their whole approach to fighting. Like you said, fighting tall and evading punches all together. But their technique is completely different. Vitali is a pure arm puncher at times, Wlad isnt. Vitali's jab has a looping hooky motion to it. Vitali avoids punches with a lot of leaning back, where Wlad uses his footwork more.