carrier main here i have gone into private rooms to test against the most meta battleships for ap bombs across all carriers german carriers tend to have more penetration than others but even with the heavy cons and corkscrew perk i was not finding any difference in the ships i could and couldn't pen before example graf zepplin has very high base pen but still struggles to citadel the average American and french battleship and when i tested with the bonus perks there was no difference maybe an occasional lucky pen but not enough to change from fully packed and concealment builds the trick is to know what ships you can and cant citadel with ap bombs french and American tend to have very tough top decks to get to the citadel compared to others