Aikman's not an all-time great, IMO. He was great for the Cowboys, but put him on a team without a dominant run game and D and I don't think he sniffs the SB, let alone wins 3.
BTW, Aikman threw 23 postseason TDs and 17 INTs at a rate of 1 INT per 29 attempts. Not exactly pretty (for reference, Manning is at 1 INT per 37 attempts and he's a "choker" without a running game).