the mane man, thou art a moron:
A dev team can only grow so large, if you want a game to be a single experience rather than a bunch of fairly cool sequences smooshed together with no real theme then you can choc your dev team full o' as many mappers as you want, same goes for modelers... But if you want to make a game that is supposed to be better than Half-life, better than the game that many consider to be the best ever you can't just make as many gigantic maps as you possible can and then stick them together, you have to have a smaller team that can communicate easily and build off of each other's ideas.
Sorry for any typos, btw.. im tired as all hell
I eat pasta!