@ Goodman7,
you have a serious syndrome of "mehanga and vilaayatee achaa hota hai" - There are a bunch of people like you that I know and have had a real comical time with them.
Let me quote you ONE very simple example.
Mercedes Benz 7spd automatic gearbox takes a specific ATF, its listed as MB spec sheet 236.14. One of the approved oils is Shell ATF 134 - which is easily available in USA for about USD 65/- for 12 qts (11.35 litres). Very cheap, It is packed so cheap that the bottles it comes in are not even sealed and the bottle surface is very badly finished.
Some weird benz owners only prefer to buy Febi or Meyle brand oil because it says made in Germany - lol, it costs about USD 130/- to buy the same quantity - WHY do they do that? they are idiots by all stretch.
Idiots why?
MB has spoken that shell, Mobil and Valvoline ATF 134 is recommended for these gearboxes, why should a person be really obtuse and go buy an oil that is not even from an oil company (btw Febi etc get Fuchs or Shell de oils). Even when the actual oil is cheaper to buy.
Now your problem of "no one has time to test any thing" then how can you take the word of LM oils just because its from Germany, Castrol is from BP in the UK, shell is from Holland. Every corporate brand remains the same around the world. e.g. Colgate toothpaste from Pakistan is exactly the same if you buy it from Harrods London, It wont feel like you kissed a "hoor" if you buy the Harrods one because its british.
As your post count increases it does seem that you are not even on the surface of oil tribology, Your shopkeeping experience is very dangerous to be used as recommendation because your experiences are only on "feel". You have nothing to back it up, just like you are using CVT oil in your shifting gearbox because it feels "smooth" - too smooth in automatic gearbox can be a disaster as the clutches are not catching when required - but you wont understand it because you dont know how it works and you think that all companies are fooling customers around the world.
Its quite simple, your android phone is made in china but it follows ONE specification which is set globally by the brand owner, What you are talking about is the plentiful fraud businessmen in Pakistan who take pride in selling fake items from all around the world. These morons go to China and buy the most cheapest pieces of crap, pack it in a container and sell in Pakistan - some even claim to be "authorised dealers" which is nothing but bull potty.
How do I know of such - well, ... I work in a facility that actually "invents" stuff for petrochemicals, high performance polymers, surfactants, urethanes and a plethora of divisions - so much so that at any given time you would be using a product of their patents
But its your choice, but remember that, "kam ilmi is far more dangerous than laa ilmi"