That is an interesting point, if you're using a Dragon type on a Misty Terrain team, it'll need to be one that doesn't use its Dragon STAB like Mega Altaria or Roost + 3 Attacks Kyurem-B.Misty Terrain also basically invalidates dragon STAB when used against grounded Pokemon (halves the damage dealt to grounded opponents, basically making it useless), so that's also a thing to consider beyond simply stopping status. Its gonna be hard to properly experiment with the terrains before this is coded, because there are additional effects that need to be taken into consideration. Grassy Terrain in particular due to it basically being an additional Leftovers for all grounded 'mons.
At the moment I think Misty Terrain will be the best Terrain, followed by Grassy then Electric. I'm going to update the OP later with examples of the buffed team styles.
At the moment, does anything jump out to anyone as broken?