Same maker, same cast, same facing (measured) same room with the same reed.
We can start a debate about the concept of "identical", but I have quite consistent experience about pieces to be able to feel what the difference is due to.
It depends on what level of precision you're working at.
Casting isn't generally that accurate a procedure, and once you start removing material mechanically you have to take into account a lot of variables - such as wear to the tooling, small variances in the way the material is held and even fluctuations in temperature during the cutting process.
Consider a Nikon pro-quality prime lens - costs a bomb, has a relatively simple design and relies largely on the integrity of the manufacture of the individual pieces of glass within it.
Many steps will have been taken to ensure accuracy throughout the manufacturing process so that a consistenty can be maintained, and yet it's still possible to find that one example of the finished product produces a sharper image than another.
I very much doubt such accuracy is used in the production of mouthpieces - which is why when buying a new piece (or a horn) an experienced player will first narrow down the choices between the larger elements (brand, model, dimensions) and then refine the choice between 'identical' examples.
It's always been thus.