Liberty Cruisers arent for use against Gunboats. They kill battleships and other cruisers. They sacrifice general firepower for the massive forward gun. Other cruisers, like a Rhineland cruiser, can cover themselves with their guns, and as a consequence, can bear down significant firepower on Gunboats. Remember, you lose a significant portion of your firepower against the gunboat class when you invest in a liberty cruiser.
I think that gunboats now are fine, to be honest. They are good at what they do and are too weak to take on a cruiser which is being pilotted well, bar the liberty one, which loses its ability to fend off gunboats in exchange for the ability to hurt battleships very much. you cant expect the liberty cruiser to be a good cruiser like the rhineland one plus a massive forward gun. There are always two sides to the coin.
