Could be just your play style or 4 games that were just an anomaly. I'd play a couple more before deciding, but the thing you're going for is realism. No matter how good YOUR stick skills are, a below average defense against a high-scoring offense should more often than not result in the high scoring offense scoring a lot of points. More often than not.
For realism purposes, it doesn't matter if everyone on here plays with these sliders and are challenged by the CPU's offense, if you are not then you should tweak them. The Bobcats (default lineup or with non-cheesy changes over the next 3 years) should still struggle to win games on a consistent basis. No matter how bad you are, you shouldn't go 10-72 with the Miami Heat. That's the great thing about sliders.
So what I would say if you continue to see the same trend, to make some slider changes. You have to find out what needs to be changed though. Is the CPU's offense not resulting in good shot selection? Up the CPU offensive awareness. Does defense feel too easy for you? Lower your defensive awareness, on-ball defense, defensive help strength, or defensive assist. CPU's field goal percentages too low? Up their shot success sliders in the appropriate departments. Knowing that Cleveland finished the season with one of the worst defenses allowing over 100 points per game, you should really struggle on the defensive end, not because of your stick skills, but because of the talent on the court. You may be great at defense, but you still shouldn't be able to keep teams like the Nuggets, Suns, and Warriors from running and gunning... most of the time.