AAA team I got to 1600 on the ladder with (forgot to mention in the paste that garchomp's speed is for outspeeding 0 speed iron treads) and 1 last thing you might have to predict around dondozo with it (you can try to setup rocks and dtail dondozo and grab chip on their attackers and try to get corviknight rocky helmet damage). https://pokepast.es/7abdb46a60d1413a
You can just run Overheat instead, since the -2 SpAtk drop is meaningless in this OM.
Ya know, since it's damage is calculated from it's Def insteaf of SpAtk....