If you're going to pluck a coach from the past and have them today, you'd have to assume that they would connect with the players in the same way they did when they were at their peak. Otherwise, the whole mental exercise is moot. Given that assumption, I's pick Landry in his prime. Super intelligent. Created a ton of accountability. Was absolutely the head of the team and was rarely challenged. His men would run through brick walls for him. All great coaches have that I think. Jimmy did, too. But Landry was so unbelievably stable as a coach.
I'd pick Landry. But I'd be happy with Jimmy, too. For that matter, prime Parcells. Switzer is an enigma to me. I don't know if he sucked, was brilliant, or somewhere in between. All the others have been puppets. McCarthy's story isn't finished yet.