This is only one smokers opinion but it seems to me that you can add condiment ingredients to a blend without changing its nature. But I don't think you can remove or substitute key ingredients and have it remain the same blend.
So, if a Navy Flake is essentially Va+Rum, then removing the rum or substituting burley for the Virginians, I would believe that the blend is no longer a Navy Flake. If the same Navy Flake was cut into ribbons, it would no longer be a Navy Flake.
Since Escudo isn't cased with Rum and since it is a large curly cut coin, I certainly wouldn't consider it a Navy Flake.
My understanding is, that back in the colonial days, sailors twisted their tobacco into ropes and soaked them in rum, to save space and for preservative measures. They would then slice off coins from the rope, when they were ready for a smoke.
From this tradition, I could see where makers of twists, ropes and coins might argue that their product is a Navy tobacco. (Not a flake though.)
Unfortunately, we don't have a standards committee with authority to settle these matters. (On reflection, better not to have such a committee.)
Language is a living organism, always changing, which can be frustrating, and pipe smokers have to learn to live with some ambiguity. For example, is there really such a thing as a balkan blend or is a balkan just another word for an oriental heavy English blend. Does adding liquor make a blend an aromatic? What is an American blend? Any burley based blend? When does a dublin become a horn or an egg bowl become a tomato - or a tomato become an author, etc, etc. etc.
Of course, without ambiguity, we would have much less to discuss on these forums. :lol: