AC2 has tons of screen taring issues, so yes, it could have been made better by a team of the same size that was dedicated to a single piece of hardware.
Also, Nintendo doesn't spend money on gaining exclusives. They just make their own software for their own system. (edit: ok, let me rephrase that, they don't spend money directly, but I'm sure they cut some deals to exclusives like cheaper liscensing fees, or possibly free advertising)








