Wlad either uses his length and size to octopus Frazier to death, or gets KO'd trying. I would bet on the former. The robotic Vitali would not be able to cope with Frazier's pressure and aggressiveness.
Wlad wins decisively. Vitali I could see struggling to land while reaching for Joe. I think the size difference though would lump Joe up late and probably give Vitali a tko or close decision win.
Not exactly ... Frazier was an exceptional fighter and a top ten P4P heavyweight for sure but way too small to defeat either Klitschko.
Frazier had way too much heart for either K brother (though they were amazing fighters, too). He absorbs terrific punishment from both but wins at least majority decisions. The K brothers never fought anybody like Joe (gee, who has besides guys who actually did fight him). He was vicious, ugly, relentless, Once he felt at home on your chest it was just a matter of time....
Joe Frazier is too small to deal with them. Wlad knocks him out after picking him off at range and laying on him anytime he gets close. Vitali overwhelms him until he gets a late stoppage.
I hate to say this, but Wlad wins this one. This is a case were sizes AND styles are decisive. If Foreman was able to push and set Joe around, then Wlad should have an even easier time keeping Frazier away and into range to bomb him with jabs and straights. If Joe is somehow able to pass throught the artillery barrage, then Wlad grabs and clinches, pushes away, bombs, rinse and repeat. Sadly I don't see a way for Joe to overcome Wlad's massive physical advantage AND dirty tactics. Vitali is a different tale. Regardless the physical gap I think Joe has at least a 50% chance of outlasting Vitali in a brutal battle.