Well Milotic, Ludicolo and the rest of the team cept for Metagross can counter Garchomp easily.
But there is a way for us to have a Special Sweeper Garchomp. A variant that employs trickery that no one would expect.
[email protected] Orbs
Naugthy Nature (+Atk, -Sp. Def)
252 Sp Atk / 252 Spd /6 HP
-Swords Dance
-Earthquake
-Draco Meteor
-Fire Blast
Send in Garchomp and most people would switch out and send in thier Grachomp counters. Or you are in a battle and use Swords Dance and they switch out expecting an Earthquake or Dragon Claw. Then hit them with a Draco Meteor. This could work because Draco Meteor is insanly powerful. (210 BP with STAB). With Stealth Rock support and all that it is nearly an instant KO.
Sure this can work on Salamence but everyone is familar with Specsmence. : /
Just sometihng fun to think about.