Something about Carroll reminds me of Bill Walsh in San Fran in the 1980s. Not so much in demeanor but in the way Carroll builds a culture that lets players play, lets them blossom and discover the full extent of their abilities. Walsh ultimately created a system of trust with his men. Carroll does the same. Just looking at Carroll's reaction in that "I just read it" clip with Lynch on the sidelines. After trying to explain the blocking scheme to Marshawn and getting the same "I just read it, coach" response over and over, Carroll turns around laughing, as if to say, "Of course these men know what to do? Who am I to micromanage?"
Holmgren, on the other hand, is a control freak. Watch the NFL Films short abotu the classic playoff game between Holmie's packers and Mooch's 49ers back in the 1990s. At one point, Favre decided to change the play in the huddle without consulting the coach. It resulted in a touchdown. When Favre came off teh field, Holmgren is shooting daggers into his quarterback. Later, in postgame, he said Favre was doing the equivalent of "drawing up plays in the dirt," which pissed Holmie off.
I love both coaches, but the coach in XL was a control freak. As a result, the team got tight when it was hit with crap penalties. The coach in XLVIII is loose, and the team follows his lead.