Not for me... if everybody whose name and jersey number is up there was there necessarily/exclusively because they won the heisman trophy, then they'd just change the title of the thing to "OSU Heisman Trophy winners".
Winning a Heisman is ONE way of getting your name on the list for consideration. There are many other factors which, in a context other than sheer/recognized athletic sumpremacy, can make an individual's memory worthy of being enshrined in the 'Shoe.
This isn't pointed at you directly general, but imo, there shouldn't be any questions about why #99 is up there. If anybody has them, they need to reflect more deeply on the reasons behind
Gene Smith calling Bill Willis "the Ultimate Buckeye" and saying that retiring his jersey "is a way to salute not just the Willis family, but the Buckeye program overall."