All they have to do is show up and yell and cheer and smile and laugh. No lines they have to memorize. What do actors who have no lines get paid? Scale minimum is what these days? I suppose to get hired to fill a seat you don't need to belong to any any theatrical union. Any body off the street will do. Gotta be smiling. Gotta yell real loud. Gotta look real healthy..chunky and rotund is even better just so chump won't feel so obese. That's about it!