Were they different from any other coaches successful to such a substantial degree? What made Barry Switzer at Oklahoma different from, say, Bob Devaney and Tom Osborne at Nebraska? The cultural milieu of those two states and Switzer's necessity to mine the TX/AR/LA markets for recruits? The milieu of the Midwest and Big Ten tempered the baser impulses of Woody and Bo, in my view, that might have been loosed were they coaching in the SEC or SWC.
I actually grew up around Woody Hayes in the '70s. I agree with you that he and Bo were indistinguishable in fundamental character (and Bo cut his teeth coaching under Woody, which made the 10-Year War of '69-'78 especially fierce.) However, I view that character as generally strong and productive. Coach Hayes was certainly irascible and utterly intolerant of losing, which led to his spectacular demise. But he wasn't nuts like (Ohio State basketball alum) Bobby Knight, to whom he was a close mentor. He was a professor of military history during the winter quarter at OSU, a deeply serious man, he truly loved and cared for his players while pushing them to the absolute edge of their tolerance for pain in pursuit of performance, and (like Knight, Bo, and nearly every other HoF coach) flawed and complicated while brilliant. "Scoundrel" is a bit much, IMO.
One anecdote about Woody of which I was unaware until I read John Feinstein's (RIP) Season on the Brink about the 1984-85 IU basketball campaign, is that when IU played in Columbus that season, Knight asked Woody to speak to the the team beforehand. Woody obliged. Wheelchair-bound, and at the end of his life (he died in early '87 during my junior year) he gave an impassioned speech about commitment and integrity. "Do as I say, not as I do"? I don't believe so.
He was also wry and funny. At the zenith of his powers, the team having won the '68 Natty and enjoyed a fabulous run, a reporter asked him if the football program tail was wagging the academic university dog. "Of course not," Woody answered, "Ohio State is a university of which the football team can be justifiably proud." I read that quip 40 years ago and still chuckle when I think about it.
As for Bo, I respect what he accomplished. Like Paterno, he turned a blind eye to dragons in the program with which he was (as a man of his generation) uncomfortable, and of which he was avoidant. Coincidentally, a former colleague's husband grew up on the same block as Paterno in State College. He knew JoePa as a veritable grandparent and a wonderful man. When the Sandusky revelations surfaced it shook him to his core for several years. These guys work at the absolute edge of the envelope to generate the successes they do. Inevitably, there's a lot of collateral damage.
I'll end this TL;DR essay by giving thanks for what we have in BB.