Very cool team! The truth is, you can't possibly support Nihi Rilla Kart Zone. There are no 2 mons in the game that dont leave gaping holes in such a team structure. The best fix here though is definitely physdef Mandibuzz over Zapdos. It swaps into Dragapult shadow ball (although since you have no fairies I recommend adding enough SpDef to live 1.5 Dracos with Mandibuzz so it can swap it.