If they tried to design a more complicated ordering process they would fail. I say just put up a big "wheel of fortune" and customers can just give it a spin. Personally I think the reason they keep it is so they can interact with customers as they patiently explain how to order. Something they all seem to do well.
On my first visit I was with a big party. My order was lost or someone else claimed it. Whatever, I drank another beer and left hungry. The second visit was successful. The key is not to think too much when ordering.
I had the gringo and jerk chicken. The meat, beans and rice were really fresh. There is a lot of flavor here. You can get a meal and a drink for around $10 and that makes this place a winner. Plus they give you a cookie too. Not a fortune cookie a real cookie.