but I always thought of battlecruisers as fast battleships/pocket battleships.
which is what your drawing is not as well.
fast battleship
pocket battleship
battlecruisers are, according to wikipedia:
A battlecruiser, or battle cruiser, was a large capital ship built in the first half of the 20th century. They were similar in size and cost to a battleship, and typically carried the same kind of heavy guns, but generally carried less armour and were faster. The first battlecruisers were designed in the United Kingdom in the first decade of the century, as a development of the armoured cruiser, at the same time the dreadnought succeeded the pre-dreadnought battleship. The original aim of the battlecruiser was to hunt down slower, older armoured cruisers and destroy them with heavy gunfire. However, as more and more battlecruisers were built, they increasingly became used alongside the better-protected battleships.