Hmm. That begs the question, do they really have enough people to design a Pokemon game of this caliber without cutting corners in just 2 years? They recently said design started in 2011.
It all depends on the team is layed out I guess, as well as how experienced they are. I would say no, but that's based less on the number of developers and more personal experience. I'm a bit biased here though.
It seems difficult how long do you think it takes?
Well Sugimori said he had like 1000 pokemon ideas back in Gen 1, they now have(as of BW) 17 artists, so thats a lot of people giving ideas/creating pokemon, they said last region of the 17 artists each of them did like 10 pokemon.