Arlington Texas really isn't known for good sub shops. However there was a good one near the house. Dino's. Should you come down for The Draft in April check it out. It's a short drive of 5 miles south of AT&T Stadium.
I've been fortunate to have a sub from Primant's on one of the trips to see the Bills play Miami.
Locally here in Granbury, I have a Firehouse, Jimmy John's,Schlotzkys and the usual Subway. I prefer The Bootlegger from Jimmy John's on their wheat with everything they have on it.