Matt Cassel was proven to be feces once he left the Pats. Any other coach barely wins 4 with him, especially if he had to come in a relative emergency. 10-6 was marvelous. I actually like Tomlin but the Steelers wouldn't go 10-6 with Matt Cassel. Nor would most any other coach. Perhaps Noll in 1976, with 1976 rules.
Only verifiable psychopaths like Belicheck (see upj's post above

) but one has to give him his due. Belicheck wins with the most amazing cast of dweebs, wieners and rejects one can imagine. Forget QB if you can. Do you think NE's D would suck like the Steelers still does, with all those #1 draft picks?