That's a reasonable theory Chrispy.
Another is the team's 'always compete' philosophy allows talented players the opportunity to display their talents quickly and quicker than might be possible elsewhere.
Encouragement to advance up the ladder if you can get it done is part of the philosophy of the team. Thus a talent like Sherman isn't forced to languish as a backup if he can successfully challenge the guy ahead of him on the depth chart.
My genuine sense is the real Sherman is a far different animal than the persona created by the media; he quietly seems to be a very genuine kind hearted man who has a superior intellect instead of the big mouth blowhard the press is quick to attempt to colour him as being.