having silk reeling refer to the worms actual movements to produce silk make sense, as well as the reference to not pulling silk too hard etc etc.
I think it's easy to get lost in generalities. For instance, "Misogi" is not just about "cleansing" by any means and "breathing exercises" are not just about breathing. General terms don't necessarily connote the full implications of what is going on, in many descriptions. When someone says "reeling silk", the uniformed picture some sort of arm/hand movement, etc., and actually you can do reeling-silk exercises separately for the head, neck, arms, torso, waist, hips, knees, ankles, or whatever. It's the way the power is used that defines the "reeling silk", not the particular movement of any body part.
I posted several times in the past that for all practical purposes, the equivalent to "silk reeling exercises"in Aikido was in the Aiki Taiso. Now most Aiki Taiso don't have silk reeling, but I've never been able to say that with complete certainty in some of the old films of O-Sensei.... there are a couple of videos where I had to go "maybe-maybe not" because I just couldn't tell for sure what he did to get to some of the places he got in his movements. Tohei I would say no... he uses only the pulling silk, although I don't think he really teaches what he knows about this area (just an opinion, not a judgement).
Ultimately, at the level we're discussing these things, it simply doesn't matter much. My point is that if you boil down correct Aikido and you boil down correct Taiji (or other arts, Chinese or Japanes), after everything boils off, you'll have the same principles left in the bottom of the pan.