Kalos starters of your choice

Well, for Kalos I think we could go for alternate types.

Like having Goomy as a starter. You have to put in a lot of work but the payoff would be worth it. Goomy would also be a non-intimidating starter Pokémon for new trainers.

I honestly want to see an Eevee as a starter but not with a forced, evolve into Sylveon mechanic. Maybe making it easier to evolve into Sylveon but still having an option to evolve into other Eeveeloutions.

Maybe Honedge could be a starter. It could be for the people who want to have a challenge in gaining the respect of the possessed sword and form a powerful bond that could allow you to wield it as a sword. this would show the trust this Pokémon has in you since the Pokédex states that if you try to wield it like a sword then it will suck the life out of you with its blue scarf hand thing

Sorry this doesn't fit the criteria of what you were asking for but I feel like if you have Pokémon that aren't the traditional starters then the should be different types just for a little more diversity and could make for an interesting battles against rivals since it won't be as Rock Paper Scissors as Fire, Water, and Grass are :/

 

My first thoughts were Clauncher for water, Skiddo for grass, and Litleo for fire. Like most starters, all of them are based off of clearly identifiable animals. Of the three of them, I would probably want Skiddo. It's really cute.

 

All that criteria leaves us with:

Grass: Skiddo, Phantump, Pumpkaboo
Fire: Litleo
Water: Binacle, Skrelp, Clauncher

Have fun with all those options....

 

Well, Water-Fire-Grass is not the only type trio; there is also Dark-Psychic-Fighting, so maybe Pawniard-Espurr-Pancham?