GLENDALE, Ariz. — The 49ers’ Super Bowl dreams are getting dimmer, and they’ve pretty much blown their shot at the Lady Byng Trophy, but three games into the NFL season they’re the early favorites to bring home the Bill Callahan Cup. Callahan was coaching the Raiders in 2003 when he said after a game, “We’ve got to be the dumbest team in America, in terms of playing the game.” One hesitates to turn the 49ers’ two-game slump, ugly as it is, into something grander.