Great job!
As we (italian players) are saying from 2-3 months, a meta made of Metanite, MSN and Flygon D is perfect for stall decks....
In Italy, a stall deck won 2 CCs and went 2 at Regional too!
Polistall is a nice deck, Grumpigstall is even better if flariados is big in your meta (1hko on ariados, and WP works on grumpig so no spider trap unless the hit a succesfull head on ER2).
Btw MSN is quite easy:
Dunsparce+dugtrio means they have no way to hit bench and have to retreat steelix or hit head on confusion just to kill fossils....
+ 4 cursed stone to put 4 damage on each of their metagross and nidoqueen!
Hope you and your dad will give a try to grumpig...
it frees a lot of space!