Wiring diagrams happen to be a perfect vehicle for carrying the principles of technicians beyond nuts & bolts. First, the simple act of color-coding helps to bring out the true wealth of your knowledge and is an excellent step in diagram analysis. Beyond that, it is an amazing tool for developing the awareness needed to get on the road to becoming an expert learner.
You should be able to isolate into two groups any leads which have continuity with one another. The starting circuit is likely to isolate to two leads, the running circuit may have two or more leads that show continuity. If the running circuit has more than two leads, you will need to determine how those leads are to be used for voltage or speed changes.
In our experience, we disassemble, repair and reassemble objects we can see and touch. Our goal is a repair. However, to repair today vehicles, we must expand our understanding beyond things we can touch, see and use wrenches on. We must apply the technician approach to learning, information gathering and analysis.
Magnetically soft materials, however, tend to be more expensive. The motor manufacturer must find that proper blend of just enough magnetically soft material to do the work required without putting too big a dent in the customer wallet.