Vegeta and Goku would fight each other in an even match, so it'd all come down to who wins between Gohan and Cell to support the other, for which there's conflicting evidence to support the superiority of either side. If rage boosts aren't restricted, then Gohan wins. Without them, it's difficult to say, but I'd probably say Cell's techniques would be enough to give him the edge and reinforce Vegeta afterwards.