These ships are mostly similar, and referred to as a class, even though each ship is different

Sparta Class Dreadnought
the 2nd Sparta Class Dreadnought
Some attributes
First Armament:from 12-16in main guns
Second Armament:5-12in secondary guns
Third Aircraft: 1x F4F; 1x F4U; 1x Zero; 1x TBF; 1x B5N; 1x SBD
Other attributes
Fourth Speed: from 10-80 knots

Sparta Class Dreadnought (Original, Sparta)

this ship, named Sparta, had four 16in guns, and was the most powerful ship in service with the (unnamed) fleet at that time. It had a secondary armament of ten Advanced 12in Guns. Her captain was named Leonidas, and no one knew his last name. it became the flagship of Leonidas' division when the fleet joined the IKN.

Sparta Class Dreadnought (Mk1, Athens)

This newer ship was named Athens

Sparta Class Dreadnought (Mk2, Corinth)

Yet another ship, this had the name Corinth

Sparta Class Dreadnought (Mk3, Argos)

Argos, the 4th variant of this class

Sparta Class Dreadnought (Mk3 Variants)

these ships were constructed during a time when a new ship was constructed every time an upgrade was available. (fail, i know. i didnt want to just upgrade a ship.)

Mk 3.1, Ithaca

Mk 3.2, Lamia

Mk 3.3, Megara

Mk 3.4, Olympia

Mk 3.5, Rhodes

Mk 3.6, Thebes

Mk 3.6.1, Modified Thebes