Think hot n fast, 275-300F. No way I'd do a low n slow smoke with this order, but that's me. I'd also use a heavy wood like hickory, mesquite, or a 70/30 mix of the two.
Personally, I'd brine the split chicken breasts in a cooler the night before the smoke, figuring the ice into the brine equation. Brined chicken is much more forgiving of mistakes and always comes out juicer. The chicken is going to take up the most room in your smoker at one time.
Use whatever rub you want, or just SPOG the butts, brisket, and short ribs. I'd skip the butt and beef injection unless you have a flavor profile you are shooting for. I'd bet the butts, brisket, and the racks of short ribs will fit in your smoker at the same time. I'd simultaneously lay down the smoke on those three until the butts and brisket had an IT of 160F or so, then wrap the butts, brisket, and short ribs separately, each with some liquid, and finish in the oven hot n fast or on the gasser side of your grill hot n fast.
While they were finishing I'd put the chicken in the smoker with whatever rub you wanted. When the chicken was done the others should be done too. I'd take the butts to 205-210F, the brisket to 200F, the shorties until they were pulling up nicely, and the split breasts to 165-170F. You could even over cook the shorties until they were fall-off-the-bone tender. Folks who don't know better think that is wonderful.
Not a perfect plan, but just something to stimulate ideas. You could even throw different veggies in with the butts while they were wrapped (onions, garlic, peppers, etc) so it all mixed together when pulling.
Guys who don't smoke won't care about bark, just flavor. Using a heavy wood will impart lots of flavor before you wrap.
Believe it or not, the total time on that cook I just described is about 6-7 hours.