Though I largely agree with much of what you said, you made some major mistakes.
First off, Holmes was scheduled to meet Foreman in 76 but got injured. Foreman went to Dino Dennis who was a similar size and type of fighter as Holmes but ended up being less durable. Second, Saddler was long gone in 76. Foreman felt betrayed in Zaire by Saddler, accusing him of doping him and sacked his team according to Foreman's autobio.
Foreman was not interested in fighting Holmes in the 90s when Foreman was in title fights. No biggie. Holmes had his title shots and never converted like Foreman did. I tend to think 9 of 10 times Foreman would beat Holmes at anytime of their careers, KOing him several times. Holmes never took on top comp while he was champ and has a lot to answer for during that time frame, though he did redeem himself during his comeback even if his style had become a boring JackJohnson grabbing style.