The full swing is easy. It is the teaching methods that are difficult to employ. If you stop using the current full swing models being marketed, you will perhaps open your eyes and look elsewhere for alternative swing models. Even the pros get confused by their own theories. It seems that every generation comes up with something different. During Hogan's time, his swing was very flat by today's standards. Nicklaus swing was much more upright. Do you remember the reverse "C" finish of Johnny Miller? You don't see that anymore. Do you remember Payne Stewart? His swing was very classical, not unlike the swing of Sam Snead.
My point is, there is more than one way to teach or learn the full swing. Trying to copy by diagram, how the pros do it, will not help you. Once you learn an easier approach, you will definitely spend tons less time on your full swing. It is the easiest part of the game. Chipping and putting separate the winners from the losers. All the rest is the easy stuff. Driving is not that difficult if you don't try to hit the ball 380 yards every time. I use the same exact swing for my short irons, long irons, fairway woods, and driver. If you use a method that makes you hit down for the irons, sweep for the diver, and have different ball positions for each and every iron, then you will be more inconsistent, in my opinion. This is just making the game more difficult than it has to be, in my opinion.
Using the legs very actively in the golf swing is a relatively new idea. During the playing days of Lord Byron Nelson, no one then considered using the legs for more power. Then there came the big muscle swing craze. How about firing the right side? Jimmy Ballard's brainchild. My point is that ideas come and go. Some are better than others. Some are much easier to employ than others. Did you ever read the Square to Square Method golf book? That was the book my father used to learn how to play. He hit his drives further, and straighter than any of his non-professional buddies. There is much to explore in the golfing literature. Open your mind, do your research, not just the current thinking.
Dont forget stack and tilt. It was very popular for a while and now its kind of fallen by the wayside.