I agree. If prohibitive or risky to get a concrete mixer in the site, a large mixer and extra hands is the way to do it.
Like I said, when I was doing my patio, the extra hands and that mixer made it go very quick and easy. Lot quicker than I thought it would've been. In fact, out of the whole project, doing those footers were the most daunting, but because I had the right people and a mixer, it was cake.
Up north of me, there are lots of places I know that were built using a mixer and bags of concrete because it was prohibitive to get a regular mixer truck in or a pumper. With enough help, the finished product looks exactly the same.