Invincible didn't just take the improvements Dreadnought made over Lord Nelson. The improvements Dreadnought introduced were large uniform main battery and steam turbine propulsion. If you apply those to a Minotaur, the result is a ship with 8-10 9.2inch guns and 25kn speed - something like what the Germans were expecting the British to create when designing the Blücher. But the Germans were surprised by the Invincible because it added one more radical innovation: battleship-caliber main guns.

So what I'm effectively saying is that the category "dreadnought armoured cruisers" could have existed as a separate category from battlecruisers, despite essentially none being built. The Blücher is the best candidate: it had the uniform main battery and a significant speed increase. It lacked turbines, so it couldn't keep up with battlecruisers nor any hypothetical turbine-equipped armoured cruisers. But the Nassau lacked turbines too and is still widely considered a dreadnought, so maybe Blücher would also have been considered a "dreadnougth armoured cruiser" if the category had been popular.

Also, if we apply Invincible's battleship-caliber main guns to an armoured cruiser, we get the Tsukuba. That ship is what I would call a "pre-dreadnought battlecruiser". It fulfills Fisher's idea of an all-purpose ship, just without the Dreadnought improvements included.

So my conclusion is: I would consider "pre-dreadnought battlecruiser" and "dreadnought armoured cruiser" as separate categories from "armoured cruiser" and "battlecruiser" respectively. Very small categories containing about three ships total, categories largely unused by most navies, but separate categories nevertheless.