I would recommend you use Sleep Talk over Leaf Storm on Rotom-C. After a WoW on Swampert it's Earthquake doesn't do much so you can Surf it out with Vaporeon. As well as it helps a lot more while asleep.
Also You should run Hidden Power [Electric] over Ice Beam since Jirachi and Tyranitar can handle Salamence, but you really have no solid Gyarados counter, Rotom-C takes a lot of damage from a +1 Waterfall.
Otherwise good team not much is wrong.