That's an excellent drill, Art.
In my opinion it can also be useful in fending off 'nasty bites' at that range.
I mentioned the case I had in Brockton, where in my investigation of it, I met Lt. Gentile, who had had the tip of his nose completely bitten off, when closing with an opponent to make an arrest.
Any time you engage at that range, your opponent is apt to 'lunge in' between your hands/elbows and take your nose off your face.
I think it could be useful to simulate unexpected bites during the drill.