If Tyson feasted on Holmes' leftovers, they'd improved from the experience if anything. Lennox feasted on Mike's leftovers then and they'd all had their brains scrambled badly so definitely weren't the same... A young Lennox being fed Larry's leftovers? Good luck. He didn't deserve to scrape by Ray Mercer who an ancient out of shape Holmes stood upside down. And he'd never keep a 19-20 year old Tyson at bay in say a title eliminator weighing 210 at 6ft5.5in.
I think it would go fairly well for Lennox Lewis, especially if he gets into the hands of Emmanuel Stewart, who would teach him the fundamentals and very sound defense, to look out for right hands that he might encounter from top contenders like Terrible Tim Witherspoon and Mike Tyson, not to mention then champion Larry Holmes. Because Lennox vulnerability was a right hand, Hassim Rahman and Oliver McCall. Lewis would be brought up gradually.
Not as well. Lewis not only needed the Olympics, he needed Steward in the 1990's. I don't think he develops as well ,and his career would have been shorter with more losses.