I do think they need a buff, or something. Hit a transport, in the undefended convoy attack mission, with 4 broadside and didn't sink it.
Kind of goes along with the entire low superstructure and flotation, once it reaches 10% and below it becomes very difficult to finish off. I've pumped broadsides into ships with low superstructure, getting 500+ damage and the percentage doesn't move. I've seen what looks like the entire ship on fire and that percentage not move. I realize there is a saturation point, but I shouldn't have to pump 3-5 broadsides from 12 large guns (10" and up) into a merchant ship with 5% superstructure health from 1.5km away just to sink it when one hit earlier took 10-15% off.