From an engineering point of view as it's something I'm involved with.
These items will be a very good fit, but they cannot be a micron accurate perfect fit, that's just not realistic.
When you have a metal shaped piece sliding into a metal groove, it is was just metal it would move.
My best guess is these rubber pads are there on the metal ones to take out the slack that has to be in there.
Even if it's just 0.1mm there needs to be a little slack in the metal to metal join, and this will allow there to be metal slack, but also keep it a snug fit when it compresses as you slip it into place.
And I agree with what's been said, with a rubber to metal join this issue is not going to be there.