As good of a coach Scar is, the expectation that he is a miracle worker is a a little overboard. Coaches need talent and healthy players to work with. If you don't have talent then as a coach you will fail.
There have been some pretty talented players that have come though this organization. Light, Compton, Woody, Andruzzi, Neal, Mankins, Solder, Vollmer and Scar has done a damn good job getting them prepared and developing them. Hes also had players that had talent but couldn't put it together here (or anywhere). Guys like Klemm, Greg Robinson Randall, Kenyatta Jones. Not blaming Scar for their failures but the guy can't save everyone.
In the end, for Scar to live up to his Gandalf-status, he needs the talent to take to his hard coaching style, work hard and stay healthy.
One thing I do know is if this line plays anywhere close to 2015 people will be grumbling that Scar should have stayed retired and Googs wasn't as bad as people think.