I had the same thing, which was weird because first it was ok for many games and then suddenly it just died. I've just bumped up the cpu run block, which is now at 70. I've had 3 games with that setting, in the first Chargers avg was 7.6, then Colts avg was 2.3 and in the third game Broncos avg was 3.4. I'll probably bump the cpu run block a bit more but it's pretty close.
On the flip side I've had to drop user run block a tad, since I was running all over opponents with any running back playing with the Raiders. I realize the Oline has alot to do with it, but still the avg's were 5.0 for Murray, 6.3 for Richard and 9.6 for Washington (he only carried 8 times for 77 yards with longest carry of 64 yards though).
I also made other minor changes, but overall I've been using these sliders as base sliders for years, love them. Thank Armor!
EDIT I just realized that the user run block was dropped to 45 which is what I dropped it to myself also from 48, so scratch what I said about needing to drop it more.