40 oxidation is pretty high for the assumption that it’s “mostly” group III; that combined with the fact that the only elements showing on this VOA is P, tells me that it’s more likely that Amsoil is using advanced additives rather than what some would interpret as “weak sauce”.
The testing done in my 75w90 thread shows Amsoil Severe Gear is a top-tier product, and physical testing carries more credibility than a UOA.
J2360 shows there are some poorly regarded brands that nevertheless pass some of the toughest testing!