Your post shows the inherent problems of trying to interpret UOA's without the proper context. UOA's are only one part of the picture in engine wear analysis, and as a stand alone tool are of limited use.
If Pennzoil Platinum has more cleaning additives than Pennzoil YB, as they claim, then is it not plausible that these extra additives are keeping wear metals suspended in the oil, rather than being deposited in the engine? If this were the case would you not prefer the oil with the extra additives? Again, I said before, drawing firm conclusions regarding engine wear from UOA's alone, and without the proper context, is unwise.