nobody needs 10 grams of creatine, not Ronnie Coleman, not Jay Ctler, no one.
This part I disagee with.
If a 160-pound kid can make good gains with 5 g of protein (I'm assuming his body assimilates the full 5 g), then it's reasonable to say that a 320-pound Coleman (with a higher LBM to boot) can probably assimilate a pretty fair % of the 10 grams. Toss in the fact he has more muscle tissue (the point of creatine being to pull water into muscles).
Of course, I've been huffing crayola finger paints, so if I'm wrong, brand me the tiny tit that I am