I think all I have done is lower the CPU Accuracy. On the default 50 or whatever it was whenever I first put these in, the only incompletions were drops or tips. It is lowered really low. Like 5ish. I still see games where the CPU goes 20-25, but for the most part the good QBs play good and the poor ones play poorly. Like Tarpley, for what used to be the Chargers. He is a 99 and generally tears me apart and goes for 70% and never throws a pick against me. And then when I played the Redskins or this past game, Bridgewater is the Skins QB and is still like a 73. Him and the Dreadnoughts(Bengals) QB's barely had over 50% and were way off target. There was 6 straight passes last game that never had a chance. His guys were open, he just lead them too far or threw it at their feet.
So even at 4 or 5 I see as realistic QB play as I have ever seen in a video game.