If you are doing 2 butts and a full brisket all at one time you are not allowing enough time. I would prolly start them at midnight, If they get finished too soon Which they could, you can wrap them and hold in a warm cooler for several hours. I try to figure an averager of 1 hour 15-20 minute per pound. 8 lb butt will average 10- 12 hours. I use the same rule of thumb on packers. This isn't written in stone as I have had some fly to the finish line and be ready for breakfast.
"Foil is a BBQ mans duct tape" my wife.