Light Cruisers basically better at fleet fights because they are small and agile. They are bad against Heavier Cruisers but better against smaller ships and Battleships. You basically need cover if There is Heavier Cruiser.
Medium Cruisers are average vs anything. I prefer Medium Cruisers because they are multipurpose ships. However Their biggest threat is Heavy Cruisers.
Heavy Cruisers are anti-Cruiser platforms. They are too big for Battleships and easy target for smaller ships like Bomber and Gunboats. If there is Battleships, you should use Artillery Weapons
There is 2 ship that is bad vs anything
Praefect and Irra.