Coaching 4 and 5 stars is different. At a P5 college level, one of the toughest things is teaching players how to be teammates. Every one of them, when they were in high school, they were the team, and everyone else had to get along with them. A three star is fighting his butt off to get a P5 offer. Four and five stars can choose between twenty solid schools. After they get to their college, you don't have a star rating, anymore. You have a player.
Additionally, a lot of them made it on pure talent, and didn't have to correct their weaknesses. Saban's big strength is getting four and five stars to play like they're thrilled to make the team and may get benched if they don't excel.
Read an interview with a Saban player, and he talked about when he got to his dorm he hung up his all state plaque, put his trophies on display, etc. He said Saban walked in and said, "Take that shit down. Everyone here has that." Saban knows how to motivate these guys without alienating them.
Recruiting IS important, but there's a reason schools like Iowa State, Baylor and TCU have frequently placed higher than their recruiting rankings say they should. SOME three stars are a lot hungrier than SOME four stars, and some coaching staffs spend all their time coaching them up. A coached up three star will put an unmotivated four star on his ass.
And yeah, if a guy gets offered by Alabama, LSU, Ohio State and Notre Dame, his star rating will go up over the same player if he gets offers from Purdue, Rutgers and Mississippi State.