Saying that benz is equal to mehran because gaadi gaadi hai is not the same as comparing two oils - oils follow a performance standard - which is set by a regulation body. Cars dont. They are unique to the manufacturer - and in that case you choose the manufacturer on their laurels.
In oils - what matters is what base stock is used and how stiffly is it additized - and that sets some oils in very different scales, e.g. you cannot take a POS grp 1 base stock and then try to blend all the additives in the world to make it some super high viscosity index engine lube - it wont work or even happen by any chance.
all of this has been simplified by vehicle manufacturers giving "technical requirements" rather than brand names of oils required.
e.g. my benz manual says to use oils in the following scale
1 - MB 229.3 datasheet
2 - ACEA - A3/B3
3 - API SJ (its an old car)
what they mean is that first I should look for oils that are certified by MB under the 229.3 sheet (e.g. mobil1 0w40, kendall euro, 76 pure, Shell Ultra etc.) - If I cannot find it then any oil meeting the ACEA A3/B3 ratings would work (there is a ton of such oils)
If I cannot find such ACEA oils then I can choose the API-SJ class and match it with the viscosity chart required - benz usually stick to 5w40 heavy oils - dheela engine hai inka.
in such case - lets take my latest purchase a case of 76 brand pure synthetic which meets the 229.3 spec, It was on sale, I bought 16 litres of it for 70 dollars. Its perfectly usable in my car and other customers too. mobil1 0w40 were selling for 100 dollars for this same grading, Liqui moly wanted 200 dollars for it.
so why should I choose liqui moly? when my engine manufacturer says that the oil I bought on sale is approved for service.
just like different dealers use different oil brands, in my city - there are 4 mercedes dealers, 2 of them are the same - the other two are different - 3 of them use Mobil and 1 uses Shell