@MattW
I'd like to reiterate a suggestion I had made earlier, which I think might be able to remedy the issue of most players becoming too highly rated later on in career mode. Each player, including the ones that are generated in career mode, can have a skill called "potential" or "growth". We can assign a value to this. That player would then only progress, or regress, to that value. I think the NBA 2K series had this in a previous version. So if Mohammad Amir's actual rating is 80 for example, and his potential is set at 85, then he would only progress in career mode to 85 in his prime years, and then as he ages, regress slowly downward.
Similarly, you could have a player whose rating is higher than her/his potential. They would then only regress until their eventual retirement.