Kevin, I would start them at the same time. That way, you are starting with cold meat in a cold smoker, and will only have to open the door to remove the smaller one. If you only have one thermometer, monitor the temp on the smaller one, and remove it when it hits 128. Transfer probe to the larger one, then double-wrap the small one in HD foil, and cover with towels in an empty cooler. It will keep fine until the larger one is done. Then, you can sear them both and serve!