Their stats are flipped,
Unovan is a better Sp. Attacker with 81 over 66 for Galarian,
Galarian is a better physical attacker with 81 over 66 for Unovan
It's the same for the defense stats.
Unovan has 99 Sp. Defense while Galarian has 84
Galarian has 99 Defense while Galarian has 84.
Score: 1-1
Unovan is Ground/Electric, so it has an immunity to Electric
Galarian is Ground/Steel, so it has immunities to Electric and Poison
Score: 1-2
Flexibility and coverage (Damaging moves)
Unovan Stunfisk learns 3 Electric moves. Galarian learns 0.
Each learns 2 Normal moves.
Each learns 4 Water moves
Each learns 3 Rock moves.
Unovan Stunfisk learns 5 Ground moves. Galarian learns 6.
Each learns 1 Bounce, a Flying move.
Each learns 2 Poison moves.
Galarian Stunfisk learns Crunch, a Dark move.
Galarian Stunfisk learns Ice Fang, an Ice move.
Galarian Stunfisk learns 4 Steel moves.
Score: 1-3
(Matchups against popular picks. Moves and type advantages only)
1. Skarmory (Galarian is better)
2. Gyarados (Unovan is better)
3. Xerneas (Galarian is better)
4. Ampharos (Unovan is better)
5. Excadrill (Galarian is better)
Final Score: 1-4 (Galarian Stunfisk wins)
Galarian Stunfisk seems overall better, but you can still use regular Stunfisk.
I'll probably never say Stunfisk again.
Stunfisk info:
https://pokemondb.net/pokedex/stunfisk