O.k....still a newbie. I'm gonna cook for about 15 people and had a few questions? Gonna do whole chickens and a butt on my WSM 18.5. First off....how many butts for 15? Next....should the butt(s) go on the bottom rack since the chicken will finish first? I plan on putting fattys, moink balls, and peppers to fill in the empty holes as munchies? Thanks in advance fellers!