I don't think its broken, per se...its just tied to Coach Prestige and it seems that coaches get too good, too fast in this game. The problem mostly comes from the abnormal number of high rated assistants that don't drop in prestige after they take a job.
For example...Kirby Smart (DC @ 'Bama) is a 99 OVR, which is higher than Nick Saban @ 97 OVR. When Kirby Smart becomes a head coach, he's still a 99 OVR.
You should be able to be a 99 OVR coordinator, but you need to be dropped down a bit when you become a head coach.
So, what happens is, you already have a default...10 coaches that are A+ coaches...however, by years 2 and 3, you have like 20-30 coaches rated A+ or A because all of the good assistants become rated A or A+.
So, you see a huge bump in player overalls (I've never been an OVR stickler) because of it.
If they patch it where assistants overall drops after they take a new job (say an A+ coordinator starts off as a C head coach), it could take care of that progression thing.
In the meantime, some of the OS people re-rated coaches that seems to delay the process for a few years.