Sealy Posturepedic UK Range naming?

Bit of a long shot, but trying to see if anyone can explain the range naming in the UK on the Posturepedic range?

We went to Stokers, and found an Elevate Ultra called Thornton which was classed as medium but we found it a little firm.

We then went to Benson's for Bed, again found an Elevate Ultra called Bronte, classed as a medium but found it quite comfortable.

The bed itself its quite clearly identical, but the obvious difference was the style of the top. The pattern was different, but the Thornton had more protruding padding and the Bronte was quite flat.

Now, if you go to Sealy direct, none of these beds exist and their Ultra medium is called a Hawking with again, different padding and patterns.

Every retail is the same, which obviously makes it impossible to compwre, and every retailer says "Made Exclusively for..."

Is there actually a difference in these beds, or is it just my placebo where maybe some beds have been out longer than others, and got softer over time? 🤔