And I still believe we should have a turtle-looking fire-type starter.
We already have a fire-typed turtle?
How about MULTIPLE RIVALS!?
This is actually a fairly cool idea. It'd be awesome if you could mark trainers as your rivals after you've fought them and then they'd appear throughout the game.
What do we have after that? Dark/Psychic/Fighting sucks
It doesn't work, you mean.
I don't see much point in the games suddenly breaking convention and starting a new type triangle; Fire/Water/Grass already have been for four generations, they each have their own elemental special attack, they are more or less equal with their resistances/weaknesses and they are all 'special' types under the old system. If you look at Grass/Poison/Ground, for example, Ground deals super-effective damage to five other types. For Grass, it's three, and for Poison, it's
one. Grass and Poison resist four types each, where Ground only resists two. Poison also can't hit Steel, Ground can't hit flying and gets no damage from Electric, and Grass can hit (and be hit by) everything. It's not really balanced, is it? Poison is hugely underpowered, while ground is hugely overpowered. Poison and ground are also 'physical' types where grass is 'special'.
With Water/Fire/Grass, they can all be hit and hit everything, Grass and Water are super-effective to three types each, where Fire is four. Grass and Water also resist four types, where Fire resists five. While this might be all in favour of Fire, keep in mind there are only nine non-legendary non-starter pokemon of the fire type. Fire is also weak to three of the most common types in most of the games (especially Sinnoh): rock, ground and water. There are also no fire-types in the games that are not weak to water. Water is the most plentiful types in the games, and grass is somewhere in the middle. Water is also the most balanced type, where grass and fire both major in special attack and attack.
Water/Fire/Grass actually makes logical sense, too; water puts out fire, fire burns grass, grass absorbs water. Why would ground be super-effective to poison? Why would poison be super-effective to grass (considering that most poisons found in nature are plant-based anyway)? Grass being super-effective to ground doesn't make a lot of sense either; all plants do to ground is
grow, they don't absorb dirt like water. Even flying/fighting/rock doesn't really work. I don't see why flying would be super-effective to fighting, and rock being super-effective to flying makes little sense either.
You've got to remember that this is constructed; they didn't accidentally decide to make the starting trio grass/water/fire, it was made that way, and I can't see it changing any time soon.