Ok, I give up

You are right. 50 is 50.
Now I have to agree that sponge hardness itself is a dominant vector, explaining everything about a rubber /now rubber really sounds strange

/ and in that regard I really can't find deferences between a sponge of 50 + damn rubber topsheet and a sponge of 50 + some socks /anyway unwashed are harder, but it doesn't matter if we stick on the 50/
The companies measure the sponge hardness. They don't measure the topsheet hardness. I did not hear anyone say that the sponge hardness indicates everything about the rubber or gives a full picture of overall rubber feel. All it is for is to give you some idea of the feel of the SPONGE.
I use this:
to boost my national issue Mizuno Shoes. Gives much better performance than Haifu Oil. True, the boost only lasts for a few hours. Just long enough.

When seeing a joke, you may ask: "why the joke? What happened that caused a joke? Who said or did something funny?"
More than one person has said that a rubber with a sponge with a particular hardness and a softer topsheet will feel different than a rubber with a sponge that is the same hardness but a harder topsheet. But what the companies measure is the sponge. It is just a reference number. This is not rocket science.
You are a good guy. You like posting information. I kind of feel like it is better to make things a joke when someone is insisting they are "right" and changing the discussion to try and make themselves "right" when they realize they did not understand what someone else was talking about.
Stop worrying about being right. See if you can add to discussions without trying to come off as a "know it all". We all make mistakes. So what if you confused sponge hardness with overall feel of a rubber. The people you were trying to argue with already know they are not quite the same. So no need to come off aggressively when you didn't fully understand what was being said.
And since the measuring of the sponge hardness is not the issue you are talking about, and you are talking about overall feel of the rubber, just separate the two issues and then the discussion will change.
As an adult, sometimes saying something like: "oh yeah, I see, two different rubbers can have the same durometer sponge and still feel different because of how different the top sheets are," would be a mature thing to do. But when someone is stubbornly insistent that they are right and they are not really sure what they are right about, it starts looking odd.
I have made plenty of mistakes. I have learned a lot from posting information I thought was correct only to find out it was not.
In fact, Suga D has pointed me in the right direction MANY TIMES.
No harm in starting off with an incorrect assumption. But continuing the argument as though everyone else is wrong is kind of immature.
BTW: That information I gave a while ago about how Xiom uses the term Aramid to mean the same substance as the Arylate in Butterfly blades: I at first posted that they were different and was given the information that they are the same from a guy who is in R&D for Xiom. He was very gracious in explaining to me how and why they did it. Sometimes we learn from starting off with an incorrect assumption and refining our understanding. There is no harm there. The question is, can you do it graciously.
At fifty-two years old, I have made more mistakes about more things than I could ever dream to count up. The issue is, can I learn from when I come out like I know what I am talking about and realize I may be incorrect.
Here is what you are correct about: two rubbers that are labeled with a 47 degree sponge can feel very different. I don't think anyone was arguing against that. But that does not mean the measurement of the sponge for the two rubbers would be different. All the number is for is to give us an idea of the hardness of the SPONGE. Not the overall feel of the rubber.
Now I am going to go use my tip top tire glue to boost my national shoe laces.