Ok, so! What I don't understand is, why are there Spartan III's on Reach (Game). But I thought that Spartan III's weren't created until afterwords (Books). Does that book and game contradict or am I missing something?

Also, Why would Jorge (Noble 5) not have been with all the other Spartan II's during the fall of Reach? 

I feel like the book and game contradict on many things. But maybe I'm wrong. 

Any thoughts? Thanks so much.