Maybe this wouldn't add up to the same timewise but if you think about the sorting you did, Rita, to stratify the chicken, build the stack, rotate (if rotating), cope(!), etc., the hassle factor, to me, is far more than that of successive cooks. Besides, I don't have to worry about much with a fairly light load in the cooker and can do other things--like sides and sauces--while each batch cooks. I'd probably do that much chicken (90-100 pieces?) in 5 or 6 successive cooks.
Some stray thoughts in no particular order:
I rarely cook chicken for large gigs. It's a PITA to me. Then again, people book me and I cook whatever I want pretty much; they don't generally have food items in mind and then call me. I don't work that way. There are times when it's happened though. For large gigs where I must do chicken I just do it inside (it's easy to brown a bunch of chicken in pans and then move the pieces to sheets for oven finishing--or just roast pieces from the get-go, like roulades), or I'll brown or grill then braise, or I'll do whole chickens as a secondary meat item, carve post cook, and serve. This works fine when cooking/serving on site.
For cooking here but serving there I'm more likely to grill to safe (160) then finish in a pan in a little sauce till done. (Part of that step can happen during reheating if needed.) This shortens the first part of the cook (if using dark meat) because you're only cooking till safe, not palatable. That happens later--and can happen much later if more convenient: just cool the pieces, fridge, deal with finishing/reheating whenever.
Cooking whole chickens then carving later is not worth bothering with unless you're planning to pull the meat off the bones for putting in something else--another way, though, to serve chicken to a crowd: in something.
Use plenty of lit fuel for high heat chicken and if doing a bunch make sure it's room temp going into the cooker. Prop your door open at the bottom, if needed, to feed in air and get your temps up. You should have no problem getting past 300.