This would be kind of really dope cos of versatily and kind of really not dope cos EVs are a bitch.I have another theory about the bracelet that we get in SM. The only basis I have for this is the 'Iwanko, Rowlet, Litten, and Popplio all hide a secret' thing, and the datamined typings found on the Japanese site with Rowlet, Litten, and Popplio's types (Grass/Flying - Ground, Fire, and Water - Fighting) as well as Popplio having Disarming Voice.
So, what if the bracelet is a new type of Form Changing that you can use in battle? Like, select Pokemon have alternate forms with the same BST and possible different typings? Like Shaymin or Deoxys - except you can change in battle as long as you have the corresponding items (in Deoxys case, have a charm made of the 4 different meteors). And Iwanko's/Starters secret is that they are the only Starters that can form change.
This could explain the datamined typings; Rowlet can switch between a Grass/Flying fast attacker and a Grass/Ground bulky attacker with lower speed, Litten may remain pure Fire but switch between an offensive stat dist. and a defensive one, and Popplio could Switch between a Water/Fairy Sp. Attacker and a Water/Fighting physical attacker.