This is the Titan Shipyards Multipack, now featuring;

Acclamator-class Heavy Battleship
Eclipse-class Light Dreadnaught
Executor-class Dreadnaught
Executor Mark II-class Dreadnaught
Sovereign-class Super Dreadnaught
Sovereign Mark II-class Super Dreadnaught

The Acclamator is the smallest of the pack but by no means weak, though it's no Executor.

The Eclipse is a stepping stone between the Acclamator and the Executor, and is classified as a light dreadnaught

The Executor is the first real dreadnaught in the pack. The Mark II sports some improvements, a modification of weaponry, and is slightly faster.

The Sovereign is the Executor's big brother, an absolutely colossal ship with an almost obscene amount of weaponry. The Mark II sports more improvements and enhanced range on it's Repeating Tachyon Cannons (one per wing) to compensate for the vessel's extreme length. It's also slightly faster and has some different weapons.