The pros can give good answers,but having been an Ironworker,if St Louis ribs is the only meat,I'd think closer to a slab each.
I'd hate to think 20 workers and 10 light slabs,and 30 show up hungry.
Not good folks to try and feed the slaw and light bread to,when there are no ribs.
![Big Grin](/static/images/graemlins/icon_biggrin.gif)