Well, in size, both of those are Battlecruisers/Battleship, A dread is much larger than that. i really like the style of those 2, nothing to complain about whatsoever, really well done. While at it, i might aswell post my latest and final capital ship. this is a dreadnought.
Erick Doe's 2 cents of wisdom: (please read, ship builders)
The difference between a battleship or a dreadnought is highly arbitrary. The nomination is best used to set aside differences within/between a single navy's own ships. Vanilla also does not use the nominer "dreadnought", so it really can't be said whether something is a dreadnought or not, from a vanilla standpoint.
In our history, a dreadnought was used as a nominer to denote ships that were similar in armament and size as the HMS Dreadnought, which was simply a huge and well armed ship for its time. Later battlecruisers surpassed that though. In fact, the HMS Dreadnought was technically a battleship. Even a battlecruiser like the HMS Hood (which sacrifised much armour for speed but none of its combat power) was superior, larger, heavier and better armed and armoured than the so-called Dreadnought. Not to mention a battleship like the Bismarck. The Dreadnought set the stage for battleships, but compared to the battleships build throughout history, the Dreadnought was a pathetic pip-squeek.
So, in short, there is no reason to assume that a ship classified as Dreadnought should be bigger or stronger than a battleship or battlecruiser. In fact, Dreadnought should be the precursor to battleship or battlecruiser.
If anything, the Dominator seems like a Dreadnought to me. Slow, heavily armed and armoured. Fairly low-tech. But probably huge and state of the art when it rolled off the production lines. The Conquest would be a battlecruiser with its relatively low armour rating but high speed and combat power; and size advantage over the Dominator. And the Paragon or Onslaught? Those could be battleships, one dated the other more modern. Heavily armed, relatively fast and just humongous and durable.
The idea that a Dreadnought may be bigger and superior to a Battlecruiser or Battleship may come from the use in a lot of space games. The simple fact of the matter is that these games resort to using the nominer "dreadnought" whenever they need a name to sound awesome and powerful, and have used up all regular hull and classification nominers.
I just had to clarify this.
P.S.
That does not take away the fact that hull-class designation has been somewhat arbitrary throughout history. Even today. And nations actually deliberatly circumvent other nation's designations. How? Why? Here's a few examples:
1.) Dutch Fluteships were the result of a toll-law created by Denmark in the 16th century. Ships passing through the Danish isles would have to pay toll per their deck-size. Hence the Flute ship, which was developed to have a huge lower deck, in which to transport goods, but to have only a slim upper deck so they would'nt have to pay much toll. They technically cheated the Danish into thinking the Flute ships were smaller merchants, when in fact they were huge trade ships.
2.) Several nations changed the designations of their modern navy ships. For example, the Dutch designation for a Destroyer is "Hunter" (Torpedo-boat Destroyer / Torpedo-boat Hunter). However, modern destroyers were not named Hunters anymore, eventhough their size and armament fitted the classification, because of political reasons. It would sound too aggressive. So, they had been classified as "Flotilla-leaders" and "Frigates".
3.) Which takes me to point three. Different nations use different standards to classify naval ships. The UK for example, primarily uses the size and tonnage to classify ships. While the USA uses primarily weaponry to classify ships with. What may be a frigate to the UK might be a destroyer to the USA.
4.) Also, when you look at history, classifications have come and gone (like Destroyer Escort or Corvette) and have meant different things throughout history.