Stones Loot

[Sheeper]

Not sure, but as far as I know evolution stones should be dropped only by pokes which are required by their pre-forms to evolve.

Not sure if it's intentional or by mistake, but following that:
- Leaf stone shouldn't be dropped by: Roselia, Tropius, Roserade, Sceptile
- Fire stone shouldn't be dropped by: Blaziken (skipping Moltres)
- Thunder Stone shouldn't be dropped by: Electrice, Luxray* (skipping Zapdos)
- Water stone seems fine.

Generally there's a little mess in hoenn+ pokes looting those stones, but not even sure if it's bug or intentional, so leaving it up to you.

 

[Hohenheim]

It's not a matter of the Pokémon that evolves with the stone that should drop it or whatever you think that makes it wrong, this is an economy matter made to help players.