[quote=@WilsonTurner]
Now, your nation may have intentionally done this, but traditional ship classes have destroyers as one of the smaller ships, battleships the largest, and cruisers acting as everything in between. The reason being that destroyers were made with torpedoes- powerful anti-ship weapons- that get in close using superior speed and mobility- something that a large ship struggles with. Cruisers, meanwhile, act as anything from larger, better armed and armored destroyers to smaller, slightly less powerful battleships. They're to take down enemy destroyers, cruisers, and aircraft with their moderate AA, guns, and armor. 
[/quote]

You are quite right, looking back I did accidentally get cruisers and destroyers mixed up (I blame exhaustion) As for the battleship/dreadnaught classifications, that is how they are classified by the Void Children.