I agree 100%, you can’t have PF strength without external rotation of the femur, but the trick is to not confuse f. ex. rotation with hip abduction (widening the knees) and turning the feet out (lower leg ). Eventually you want to cultivate PF strength during standing and walking too, so you want that ext. rotation going on without walking with wide, turned out legs 🙂 Biomechanical evaluation will show that the geometry of the joints, muscles, tendons, and ligaments will allow a lumbar curve with the heels on the ground, but if the lower leg is turned out, the soleus, achilles tendon, and plantar fasia tighten making this position “feel” impossible.
And you men out there, you’re curvature is exactly the same as a woman’s. Your lumbar curve is missing as well, and, don’t you want to keep your organs from resting on your prostate?