Back when I worked for a company doing installs we would get a 100cy load of mulch at a time and four to five guys spread it in a day pretty easy. Run a backhoe and skid steer to dump into the beds. Two guys with rakes to knock it down and one guy on his knees to get under shrubs and check thickness. We fertilized shrubs and put down preen at the same time. I considered it an "easy day" compared to planting, edging, and grading. A LOT depends on how the crew works together; we were awesome.