>>35506787I'm legit shocked there hasn't been a ground gym as the first gym yet there's been 3 regions where you start with a rock gym.
Swinub would be a good start because it's weak to all 3 starter types.
Then I'd go with Trapinch because it's slow and frail, but packs a punch. Sort of like Roark's Cranidos, but with STAB.
The ground gym's TM could be dig, which would help kids who got lost in a cave or something.
Alternatively, other pokemon who play differently than their evos, like shelmet and karrablast for a bug gym.