Silver Surfer solos. Doctor strange can solo if he doesn't get blitzed by spectrum. Hulk only loses to spectrum and if BFR is allowed I guess Mrs.America can beat him. Namor literally loses to everyone on the team (assuming that black panther still has the tech he had with him before secret wars since we don't know anything about his current tech aside from Kimoyo Card).
While Carol/ Chavez can potentially be knocked out pretty easily, Chavez may be able to BFR members of the Defenders if protected well enough. Blue Marvel and Monica can definitely hold their own. Black Panther, if he has prep, can also hold his own. I see Defenders taking this most of the times; I will say however, that if Galactus joins the Ultimates, they're going to win almost every time.