You're only making a fool of yourself! Anybody who knows about boxing will said the same thing. Tyson only looked faster because his opponents were high on crack........
To answer the OP's question: probably not. Though it has little to do with whether modern heavyweights are particularly taller or pack more muscle.More to do with the lack of quality trainers and decent sparring,necessary for a talented,shorter heavyweight to develop the technique to close in and get inside a bigger and taller opponent.
Tyson, Marciano, and Frazier are 3 of the 12-15 best HWs of all time so that's saying very little. Toney's HW resume is nothing, Tua is a perpetual challenger at best who is now well past it.
Smaller guys are sometimes the toughest for a big guy...They're a smaller target, have a better center of balance and can hit with full force closer than a taller guy is use to...Just because the Klits don't have any good inside fighters to deal with, doesn't mean the Dempsey's, Marciano's, Frazier's, Tyson's, etc are done forever...
You're forgetting that Rahman koed Lennox too. But that's irrelevant. Head 2 Head , Tyson would struggle vs specimens like these. You saw what happened in their rematch. In a nutshell , Their opponents just have to hope to land a lucky punch. ( maybe that's what Haye was hoping for ? )... Who knows , maybe Haye could beat Wlad if they had another fight , or 5 more fights. Maybe he'd have 4 straight losses but would manage to ko the guy once in their fifth fight ? The point is , Head 2 head.... Guys who are big and skilled would always be a nightmare even for prime Tyson. Head 2 head , Tyson couldn't beat Holyfield on 2 occasions. And that's what... ? a 6'2 guy ? ... I'm not saying that Tyson would be totally helpless against them , but if we're talking "head 2 head".... He sure as hell would have his hands full vs these guys. Prime Tyson vs Prime Vitali or prime Lennox or Prime Wlad.... i'd say he'd have a 50/50 chance. Maybe he'd managed to ko them if they had several fights in a row...Maybe even Tua could beat lennox if they had 4 or 8 fights....Or not. Brewster , Byrd...How many times can guys like these repeat a victory like they did ? How many times can Rahman KO Lennox ? Maybe he'd repeat the KO in a 3rd or 4rth fight ? But it's not likely. Big and skilled guys like these would always have the edge.
You should look up the heights of Tyson's opponents before he went to prison, almost every one was 6'3" or taller with only a few exceptions...Height was not Tyson's problem, it was too much time in a cell and very little training after...Your point on Holyfield should tell you the opposite of your deduction... Also, Tua was never anything like Tyson...Tua had only a left hook, terrible footwork, and a frustrating lack of aggression...
Novics to the soprt of boxing like The Great want to use the old fighter "B" beat fighter "A" and fighter "C" beat fighter "B" so fighter "C" would clearly beat fighter "A". But that argument has been proven wrong many, many times before.