>>291014931. Garchomp isn't slow. Base 102 was basically perfect in gen 4 and it's still just about perfect for scarfing.
2. Garchomp is surprisingly bulky and can run defensive sets.
3. Garchomp's typing affords him pretty decent resistances to common attacking types as well as an immunity.
4. Garchomp has extremely good double STAB. Only resisted by levitating steel/fairy types.
5. Garchomp gets a great movepool with access every move he could ever reasonably need minus reliable recovery.
6. Garchomp got a very good HA.
>HeatranHeatran has a fucking million x4 resists. Grass, Bug, Ice, Fairy, Steel, Fire/Poison immunity, plus some nice x2 resists.
>DragoniteMultiscale, high BST, massive movepool
>SalamenceTwo good abilities, one of the most retarded megas, amazing offensive stats, massive movepool that allows him to fill almost any role
A lot of fucking things have to come together for you to be able to work around an x4 weakness. Jangmo Fett looks like he will be slow, probably won't have as good of a movepool or special stats as these, doesn't have much in the way of resistances or immunities and his ability, while useful, probably won't let him get anything done.