Fennekin has 307 in Stats
Chespin has 313 in Stats
and Froakie has 314 in Stats
When they evolve to their next stage they have:
Fennekin>>>Braixen has 409 in Stats
Chespin>>>Quilladin has 405 in Stats
Froakie>>>Frogadier has 405 in Stats
When they evolve into their final stages they have:
Fennekin>>>Braixen>>>Delphox has 534 in Stats
Chespin>>>Quilladin>>>Chesnaught has 530 in Stats
Froakie>>>Frogadier>>>Greninja has 530 in Stats
So they aren't really balanced at all on top of this Chesnaught has one more weakness that the other two.
Fennekin, Chespin, Froakie, were all revealed to the public at the same time along with Xerneas and Yveltal. They were first revealed on January 8, 2013 as part of the Pokémon Direct broadcast.