Garchomp is really awful in this metagame and does not deserve more than an A Rank in my eyes, B Rank seems better suited for it as a matter of fact. Garchomp does NOT, by any means, outclass Terrakion. It is slower, has less powerful dual STAB, and is weak to more of the OU metagame in general. It has an incredibly difficult time pulling off a sweep because it's so hard to get an SD off in the fast-paced offensive metagame we live in, and its Choice Scarf set is a joke, outclassed by Landorus and Genesect alike. Even the bulky SR set is outclassed by Landorus-T. Garchomp for B Rank. It's not what it used to be.