If it's not in that thread, there are 2 others I was active in that were Madden 12 threads about improving Madden 12 gameplay.
If you can't find it in those, I have it somewhere on a spreadsheet. kcsam did some testing, then I retroactively tested several Madden games. All tests were done with everything at 50 except the one setting being tested. I stop watched CPU QBs and recorded the amount of time they held the ball, if they were sacked, by whom if so, and if they threw a pass, or threw the ball away (never happened).
I had recorded well over 1000 tests at one point into an excel sheet, mostly in relation to stuff about O and D line play, like the gross differences in sacks given up by left vs right tackles and sacks by RDEs vs LDEs (if you haven't noticed that issue, don't start looking for it...). If you're interested I can try to dig up the excel sheet and post it if I can find it. PM me if you want.
They must have changed something with the penalty sliders between 12 and 15 if that is the case. Because on 12 the highest and lowest Intentional Grounding settings both produced a consistent amount of CPU throw away animations, none.
I remember reading about this back on either 05 or 06. Mostly the same stuff. Didn't test anything myself til I was playing 12.
Roughing settings might be flipped. I don't recall for sure. I didn't test and record results for those. I can't remember who did, but someone had info on it being lower roughing setting = higher defensive aggression. The logic being that defenders are less concerned about being called for penalties, thus play more aggressively; however the animation for roughing should be more frequent at higher settings according to the Madden Penalty Theory, thus more aggressive at higher settings, but I can't say for sure.
Defensive / Offensive Pass Interference needs to be set at 1 for sure though. I tested that and the difference is plainly obvious at 1 vs 100. Which also should go against Madden Penalty Theory, since aggressive interference animations should be more frequent at higher settings. But in my experience testing, they were not; instead they are blatantly timid at higher settings, seeming to actively avoid confrontation and penalties. Really easy to test though. Hit practice mode and throw the same route to the same guy from the same play 10 times in a row at 100, then change it to 1 and repeat. Highly doubt you'll need to do it more than 10 times to see the difference.