youALREADYknow, I have been saying this for years...YEARS. In fact I gripe about this in all other games as well (NBA 2K, NCAA, MLB 2K, NHL). The only dev team that can get it right seems to be the Show! Everytime there's a wishlist or impressions thread I'm always asking "hows the sim engine". Haha, just check my post history :-P.
Madden has had this issue since I can remember. I think they came close to nailing it last year and this year but there has been one or two mishaps along the way. 12 had punters in the passing stats and QB%'s were laughably low leading to bad QB ratings. 13 has no assisted tackles. If it's not one thing it's another.
I remember Madden 05-08 on last gen couldn't get ANYTHING right. My saving grace was Madden 08 using
NZA's editor and guide. On PC, this bad boy would automatically tune coaching sliders to generate great stats. But now since there is no more PC, we're left to manipulate on our own. For instance, in NCAA I gotta manipulate all the coaching run/pass sliders to get anything close to realistic stat outputs. Oh, and remember NCAA 06? Considered NCAA's GOAT but the sim engine generates about 20-30 less plays than in real life leading to REALLY low totals.
I doubt they'll ever create a real true sim engine considering a great one could be a game all in it's own like OOTP or Baseball Mogul. I'm pretty sure they're using the same engine they've used since last gen and have been just tweaking it ever since. If I could have one upgrade for future Maddens it would be a great and varied sim engine. I would be ecstatic. I would give anything to have a gamechanger or BE a gamechanger and fly down to EA and spend all my time analyzing stats and coming up with precise tweaks to generate a better sim engine.
But alas, it is not a high priority. I remember in 10 a developer actually asked for feedback regarding the sim engine and released a comprehensive list of tweaks and discussed the logic of it. In fact, I think it was Josh Looman. But since then I haven't heard a developer say a single thing about it and as you can see, 13 still doesn't have assisted tackles!!