You've gone with Overkills methodology for figuring out what is better, which he uses in the absence of more detailed testing data that none of us will get hold of.
The number of certifications is very similar. There are multiple European flavors of Helix Ultra and an overall trend there of having manufacturer specific oils. Some of these oils could have less certifications than M1 or PU Euro 5w40 but could be better for the intended application. PUE 5w40 could be better for Ferrari. M1 0w40 could be better for the Nissan Skyline as they used it during development. Either Pennzoil or Mobil could tweak their formula and some test results move in favor of one or the other.
One of the best things to read is the VISOM Mobil vs PAO Mobil presentation. You get to see actual test results between the two. Some things are better, some are worse. It still gets the same approvals. Cold starting was worse so for some Canadians, old M1 may have been better than new M1.
This is also why the Amsoil testing is helpful. If you're truly trying to find out the best oil, you need to know what information you seem missing and we are missing a lot!
So my approach is to buy what meets spec and see what my butt dino likes. Even with that Mobil doc, I am no wiser as to whether new Mobil is better or worse than old Mobil. But I'm sure my butt dino could tell me.
Also, we have to stop the references to Belgian Castrol. My Castrol 0w40 is made in Germany. Some have 0w30 that is made in Belgium. Some have product that was made in the opposite country. Let's give out the grade we are talking about and the country.