If your entire party has a B seat or smaller, you should have no problem sitting together at the back of the plane. Like a PP said, there's no need to hurry off the plane if you've checked your bags as you will have to wait at baggage claim anyway.
We love Southwest and I wouldn't call it a cattle call for seating. They are effiicient which helps them stay on time more often. You have an assigned place in line and everyone boards orderly. They have several direct flights to Orlando, are priced much lower than their local competitors (Frontier and United) and don't charge extra fees for bags, changing your flights, extra legroom, snacks, non-alcoholic drinks, etc.