LOL! It seems it's just you and I on this folder, so I hopr you don't mind me adding in my 2 cents again.
You can't use your inside arm to get a sweep because of how you shoot/penetrate. Using the inside arm is the Coach's suggestion (and a darn good one) for getting a single in a Wrestling match. However, you can (and for years it was The way) get away with using your outside arm to start, ESPECIALLY in a MMA environment.
The only person that will be busting out a Wizzer on a person AS HE IS shooting is a good Wrestler. IMO the coach is talking about the Wizzer from the other Wrestler's Sprawl, but left out that detail.
In other words, you shoot, he Sprawls and then Wizzers. Your typical MMAer doesn't usually Wrestle at that level. They MAY Wizzer AFTER you have the Single and are standing up where they can reach your arm, but I rarely see non-Wrestlers using the Wizzer effectively on the ground. When you are shooting and getting leg control, most non-Wrestlers bend over instead of Sprawling directly down, hipping in, and getting the overhook to work the Wizzer because of how low your grip is compared to when they typically use the Wizzer: against a bodylock.
Ultimately, your set-up (w/ off-balancing), good head position & forward pressure, as well as not dilly-dallying for your finish should cover the bases so to speak. On someone with more experience or a good Wrestler, you are probably better off using your inside arm or going for the Snatch single or even the Sweep IMO.