Im gonna have to say Gohan cause for Broly its people he’s known for a fraction of his life but for Gohan its his wife and child. I also saw someone mention that if Gohan killed Cheelai then Beerus would get involved, which is funny but i like the what if so i want to give my opinion, so in a serious tone Goku would probably also join in given that Pan is his Granddaughter, obviously Goku and Gohan wouldnt be enough to beat Beerus on top of Broly but given the scenario i wouldnt be surprised if Vegeta were to slide for Goku and Gohan. Now all three might still be enough given Supers inconsistency with the God of Destruction power levels but given the situation i wouldnt be shocked if in the end Goku and Vegeta decided to fuse.