If the opponent doesn't pass from the 23 set, the simple method is to a rule for Normal or Nickel defense (not Goal line) with a 100% run key.

The 113 and 203 Personnel Sets
The first two sets that I look at were kind of covered in the Basic thread. When scouting the 113 and 203, I'm looking for one specific thing: do teams run out of these sets?

If my opponent runs, and especially if he runs the HB Counter, I want to know when he is running out of the set. I will quickly open another tab and look at the last game that my opponent played and keyword search for specific plays. In my experience, most people that run out of these sets typically do so on 1st or 2nd down, and sometimes, 3-Short.

If my opponent does run out of those sets, and I can quickly find the pattern for when he runs, I'm going to create a rule that goes to Normal Defensive Backfield so that I have all of my LBs on the field at once. I'm also probably going to Blitz 1 or 2, but stay in a Neutral key. I'm only going to do this for the downs where my opponent is most likely to run these plays.

Remember that your Base Defense is going to default Nickle against the 113 and 203. So it's better to have the rule here to go back to the normal backfield.

If my opponent doesn't run, Base Defense.

...

Goal line sets - 221, 230, 311
There are two goal line defensive plays you should keep in your playbook and that is all: Attack #3 (or 1 or 2 doesn't really matter which, 3 is my favorite for reasons) and the 3-Deep Man. The 3-Deep Man play is the only Cover 5 GL defensive play.

The first thing you need to do is override the line up and move the LB that plays behind the DT to the LDE2 spot and bring your FS into the LB spot. That puts your three LBs and Safeties on the field at once instead of bringing in a second LDE, which is not going to help you.

The reason for the override has to do with when teams pass. If your opponent strictly runs out of one of the GL sets, you build a rule that will counter with your Attack #3. If they run and pass, then you build a rule that counters with your 3-Deep Man. If they strictly pass, then you have options: counter with the 3-Deep Man defensive play or run a Normal/Nickle defensive backfield against the set.

Bonus pro tip: I've seen a lot more people running the 311 PA Bomb without running any other plays out of the 311. This is silly, and not just because I hate the play, but because it's really easy to counter. Almost every defensive playbook has the Normal Defensive backfield Double WR1. This play is a Man Secondary, Blitz 1 play. Want to know why I have that memorized? Because I've built so many rules to cover just this one play.

Blitz the Run
Most players have known for a long time that the Blitz 2 is the way to go, but I don't know how many of them have figured out the why. Blitzing in MFN right now is essentially run blitzing in that the LBs attack the gaps. When you know your opponent is most likely to run, Blitz 2 with abandon. Your LBs will fill the gap, and hopefully, your DL will hold up the OL.