NL
Well at least you are answering the question this time.
Why don't you rate ACs nice classic answer then?
I had thought that in addition to ACs clean and simple justification of underslinging that there was also an advantage in trying to bring the CoG and the 'Center of Forces' for the blades closer to the same plane with the teeter hinge. ie an attempt to keep the forces inplane with the teeter hinge.
(thereby reducing the moments (with similar considerations for vibration and weight as you allude to) that the teeter bolt has to resolve (in the vertical plane which is parallel to the teeter bolt)), does that sound like it has merit?
Straight loadpaths through the head and 'packaging', hmmm maybe