If they would have fixed Pro-Tak instead of throwing it out, we might be there.
Take out the magnetized/suctioning of players and the whole "Pro-Tak moment" forced aspect (and breaking the tackle and walking in for a TD), and you have a working gang tackling AI behavior.
Heck, go back to what M12 did - you know when we could have multiple players hit a ball carrier to bring them down and get lots of assists instead of going games where guys look like they did nothing because they had 0 solo and a bunch of unrecorded assists. (and yes, I know M12 had the pancake bug)
I get that M12 was purely "canned" animations, but the game is ALL animations - any game is, animations and hit boxes.