Brennan and Faust were really from a different era where recruiting wasn't quite as pivotal. Davie and Weis were better comps although even then recruiting hadn't reached the level of importance it does now. Davie is a pretty legit comp as a successful DC replacing a successful coach, but he wasn't much of a recruiter. Weis was.....Weis. He could recruit and had been successful, but his personality and arrogance probably doomed him. Also, the table wasn't set as well when he got there. Markus comes into a better situation as we are already close to elite and his recruiting chops could put him over the top IF he can make the adjustment to being the HC successfully.
No way of knowing how it'll wind up, but his recruiting should be a big boost while he works out how to run a whole program and his engagement and work ethic make me believe he'll get there. The question is more whether he'll get there fast enough since expectations are pretty high. I'm hopeful, especially since there are a number of other younger HC's who've had success recently, but your right, it's no where near a guarantee.