[Klaus]

Why do we want to test the camera's white balancing capabilities?
Such an approach would make sense for a static WB setting. How many people are running around with grey cards? Yes, you do that in a studio environment but in a studio environment, you can recalibrate your WB at any time when changing a lens (and pros have multiple calibrated cameras anyway).
I continue to doubt that there's a "skin tone" topic in digital for the average mortal. If you find skin tones to be better or worse these days, it is a discussion about contrast in my opinion.
If "skin tones" were relevant, the same discussions would come up with landscape, architecture etc. pp - because "skin tones" is about color reproduction and that applies to everything.
Based on my experience, there are indeed substantial differences in color reproduction ... between cameras (their individual profiles) ... but not between lenses (in AWB mode).