Where did we see LaForge and Riker were in the same graduating class?
I was under the impression that they were around the Academy at the same time with Riker having had just gotten out and was committed to an assignment still around Earth (such as the Shuttle Run described in Chain of Command) while LaForge was in his first or second year.
I *DID* get the impression they knew each other from the Academy scene, but not necessarily as class mates.
If LaForge and Riker both WERE in the Academy together, I would have accepted LaForge to be introduced AS the Chief Engineer, not fighting for the promotion to that posting. After all, LaForge was a military brat growing up --- I'm sure he would have gotten some form of push if by nothing else then his parents talking him up to his CO.
But after all that's said, its also fair to point out that there's no way any of these facts would have bearing on the first season since these facts didn't evolve till much later :-|. It's not exactly like the character bios were THIS descrip before starting season 1.