The simulation is VERY VERY VERY defense heavy, most quaterbacks dont even hit 3000 yards by the end of the season which is really weird to look at, and most games have at least one team in single digits, basically offense needs to be balanced with the defense.

That's because you're in a roster only league. I used to own Xenia Tornado and had impressive skill players, yet struggled to crack double digit points. Offense opens up when us humans can pick the plays.

Yes, the default game plans in rosters only are so bad that it's difficult to produce yardage and points even if you have very skilled offensive players.