Stone Edge is more likely to miss, but has more raw power. But Rock Slide is a great move, providing a chance to flinch. Which is better for Shell Smash Minior? Here's my current set:
Minior-Indigo @ White Herb Ability: Shields Down Tera Type: Flying Earthquake Acrobatics Shell Smash Rock Slide / Stone Edge
Minior-Indigo @ White Herb Ability: Shields Down Tera Type: Flying
Minior is pretty useless in National Pokedex RU. Its meteor form lets opponents attack it while it tries to set up, and 60 base HP and 5 weaknesses make it pretty easy to check regardless of what form it's in. Even if Minior does successfully change into core form, its attack stats are still worse than a lot of other Pokemon. source Here are some movesets that you can use instead.
Barbarnacle @ focus sash Ability: tough claws Tera type: water EVs: 252 Atk / 4 SpD / 252 Spe Jolly nature - shell smash - liquidation - stone edge - stealth rock
Drednaw @ white herb/focus sash Ability: strong jaw Tera type: water EVs: 252 Atk / 4 SpD / 252 Spe Jolly nature - shell smash - liquidation - stone edge - ice fang