Genesect isn't going to switch into Garchomp before it knows what kind of set Chomp is running. CB EQ is a OHKO. Fire Fang kills. Fire Blast kills. No Genesect user in their right mind will be hard switching into Chomp. Feel free to slash in Dragon Tail and Fire Blast, two other good moves that I neglected to mention. The last moveslot is really up to whatever move suits the team best. And don't hate on Protect, Genesect never sees it coming. The smart ones U-Turn expecting a switch, the dumb ones Ice Beam expecting you to be as bad as they are. Either way, they're in for a beating. Protect is good on almost anything, I don't see why Chomp should be any exception.