Admittedly what I am about to say relates to large marine engines, which are a completely different animal and has little relevance to automotive engines but it may be of interest given the topic. In my younger days I sailed on a ship in which one of the major lubricating oil suppliers contributed to the cost of the main engine and auxiliary engines to use it as a floating test bed for research and development of new oils. The main engine had three separate cylinder oil systems (three groups of three cylinders with dedicated systems) and the sump system for the main engine could quickly be reconfigured to test new oils, different filters etc. Each of the auxiliary engines often operated on different oils. As one of the ship engineers (I was second, or first in the US system at the time) it was a pain in the behind as we had to pull pistons and liners, open up bearings etc almost every port to do measurement and inspection and the lube oil systems were horrendously complicated with all the different tanks etc. The oil company provided fitters to do a lot of the work but it still needed a lot of my time especially. However, long story, something that was very consistently demonstrated was that the important bit was viscosity and maintaining filter efficiency.
In text books and journal articles cylinder oil TBN is always presented as a major factor for piston rings and liners yet the tests showed no real correlation with varying TBN by ridiculous amounts and changing fuel sulphur content and liner wear. Similarly, all the various additives, detergents, anti-oxidants, stabilizing agents etc they add to oil showed no real correlation with/without in bearing condition. However, that didn't stop them marketing oils with various additives and planting papers in journals demonstrating the value of various additives. More than once I almost wrote to technical journals and my professional institute in protest at some claims they published but in the end decided my nicely paid job was worth more.
A few years later I was involved in similar tests working for a classification society and the results were consistent with my earlier experience, get viscosity right and keep oil in good condition (i.e. filters and purifiers).
Sorry for the diversion.