They’re not identical. You can have thin flatwork at the edge of the magnets or thick and have the magnet protruding. Is your magnet fat or .187? Etc. I haven’t wound enough to know how much small dimension variations contribute to sound if doing apples to apples so you may have a point there but dimensions for sure matter on your resistance readings. A fatter coil will take more wire per turn. Anyway my point is that comparing DCR across different manufacturers may not be accurate. Tomorrow I’m going to wind a Tele neck pickup with 42 awg on a tall bobbin. If I wind it tight and get a lot of turns someone might think it’s a low 43.