I wish i could speak italian sometimes, especially when i have to explain choices... XD
Well, you see.
It was as hard as hell for us to change the starters. We all do prefer the older ones. But just look at something different than concepts and sprites.
They were two fast starters (Dodeed and Frilzard) and a medium (Toofin, which was rather fast iself again) starter which is impossible to keep in a pokémon game, for stats and tradition.
We couldn't make Dodeed a slow starter because its evolutive line (the pursuit pokémon cannot be slow), then we couldn't make Frilzard slow or medium because it is fast itself, by being a lizard and then an excellent runner.
Toofin and its evo couldn't have become slow anyhow because of the design.
Please, i know why you complain the previous trio, but it couldn't be correct anyhow.
So we had to change...
You may know that the older three pokémons are indeed starters from three different fakedex projects from our spriters. So they're balanced following this rule with they're companions but not one each other.
Well, that's it more or less. Now, also, there are two bipeds and one quadrupedal animals, so they're balanced as the official ones. ^ ^
There are many things to look at when making a pokédex and starters are as far the most difficult to choose. No matter how much you good are at spriting or making concepts... you have to mind at many other things such as gameplay, movesets, interaction, tradition too!
Try to watch them as they're the only true starters of the dex... i wish them to be loved just as much as the older were... D: