Well, I think, if you look at the teams closely, it's always: one calm boy, another talky boy and then, a girl. So, I guess Kishi just made that team like that so they could do the Ino-Shika-Cho thing.
Zetsuboushita|ROW ROW FIGHT THE POWAH! «°-°«
Yeah I noticed it too, I think it's because Naruto started the academy before the others.