Both men fell off the same coaching tree. And they have a great affinity for one another.
But that's where the similarity ends.
From a football coaching standpoint, Eric Mangini and Romeo Crennel couldn't be more opposite of each other.
The manner in which each man handles his job, especially through the media, has caused the fans to see two Cleveland Browns coaches in two completely different lights. And it's not a flattering one for Crennel.
As a result, fans have now placed Mangini, even though he hasn't coached one game for the Browns, on a rather lofty pedestal after watching four years of bumbling and stumbling by Crennel.
The old Browns coach and the new Browns coach are polar opposites when it comes to managing the job. And it isn't all about just the X's and O's of the game.
Mangini looks comfortable when speaking to and dealing with the media. Crennel almost never looked comfortable. In fact, he often looked ill at ease. It was almost as though that part of the job was a necessary evil.
Mangini expresses himself well. He has no problem communicating. In fact, he seems to relish it. Crennel seemed to grasp for words. He wasn't exactly inarticulate, but he was in the neighborhood.
Mangini seems much more forthcoming. He answers questions directly and on occasion feels the need to embellish his remarks. One had to yank information out of Crennel.
The new coach, at least for the time being, is glib. That could change as the regular season approaches. But for now, he explains things in a language that doesn't seem complicated. Crennel relied all too often on well-worn clichés.
If you have to be reminded which ones, you haven't been paying attention.
Browns fans aren't used to seeing a coach front the media and speak plainly. Perhaps that's why Mangini comes off as a genius. Compared to his more simple-minded predecessor, he's a relative breath of fresh air.
Mangini is smart. There's no doubt about that. And he displays all the characteristics of a perfectionist. Like his mentor, Bill Belichick, he's a thinking man's coach. Crennel was just the opposite even though he coached under Belichick.
Mangini is new school. He speaks a football language with which the old-school Crennel is either not familiar or chose not to share.
Now whether all those positive attributes about Mangini pays off when it comes to actually coaching a football team remains to be seen.
There's no question he has quickly gotten the attention of the team with his cerebral approach. His attention to detail borders on the fanatical. Nothing wrong with that. Only question here is whether the players will take kindly to his more demanding ways.
Crennel unquestionably was a players' coach. Veterans swore by him and although the club's record didn't reflect that respect, their devotion to him was unmistakable.
If anything, Crennel was too easy on his men. He didn't challenge them enough or in the right ways. They needed kicks in the hind flanks and instead received undeserved pats on the back.
The old-school approach can sometimes cause a coach to pull back with veterans at a time when harsh prodding is demanded. Crennel gave his veterans way too much credit for being well prepared and it cost him dearly.
Mangini, while relying heavily on the veterans he brought along from the New York Jets, is bright enough to realize that sometimes even veterans need to be coached and can't rely on their leadership to get them through.
So while Mangini comes off as a relative mental giant, fans tend to lose sight of the fact he has achieved mediocre success in his first three seasons as a head coach in the National Football League.
Judging from his start with the Browns, he will not be any different in Cleveland than he was in New York. He has a basic philosophy and, from all indications, plans on sticking with it. Again, nothing wrong with that.
The greatest challenge he faces with his new club will be to convince his men he knows exactly what he is doing and to have faith.
Although he has players who believe in his approach, notably those who followed him to Cleveland from New York, there will always be those skeptics among the players to whom it must be proven.
If the results on the field match the intense preparation that is certain to precede every game, then Mangini will have his converts.
Until then, all the fans and media can do is wonder why they had to put up with four years of relative ineptitude from Crennel.