Jimmy Johnson? Who, IIRC, had some friction with Jones caused by the claim for credit for their success, and only recently patched things up.
Granted, Barry Switzer could be used as a counterpoint to that, but he managed to get a ring, albeit probably riding on the coattails of Johnson's teams.
In many ways, the Cowboys are very similar to the Raiders, in their past history of success, and more recent failures, caused by a litany of bad decisions, made by their headstrong owners who should probably ease off and let what good people they have do their jobs. Jones and Davis were buds, and peas in a pod.