If we look at WW2 and to be fair, airfix, with the KGV, Warspite and Nelson. allows you to produce most of the battleships the british used in WW2. They'd need to produce the royal oak/revenge class to have them all. The problem is we've done all these kits. the same for the german navy. it's a catch 22. airfix doersn't want to invest in new models if there's no market, but they are killing off the market because there's no new models.