Hi ficcion, i dont know if someone already suggested you this but i think that you should try a different spread for Stoutland. EVs: 80 HP / 252 Atk / 176 Spd with a Jolly Nature
let you outspeed and kill 2 very common scarf users, such as Terrakion and Keldeo, (and, why not, latios) which, while are not a problem for this team because you can already handle them, can stop your stoutland sweep.
In addiction, you can always outspeed +2 dragonite and you dont have to tie with adamant mamoswine even without the sand.
Other than this, good job!