Surely the on ongoing theme here is that, big ships of inferior quality will fall victim of slightly smaller ships of superior quality. Which is the point of this thread. The game is meant to be sandbox and allow you to make your own decisions. Imagine if you did build ultra modern SHBBs to rule the waves, equipped with range finding radar and modern AA, fire control with big guns might be difficult but if you can accurately calculate range and vector and open up first what does it matter if the smaller guns of the smaller ship are more accurate. They won't get the change to use them. Its not like we're asking for history to be rewritten and to have a super Yamato-class battleship. We're asking for the option of building our own SHBB to our chosen standard. Imagine an Italian Navy Equipped with SHBBs built in 1940. Could they turn the tide against the numerically superior but smaller (sometimes out dated) RN vessels. Instead your left with the option of a rather useless historical footnote. (or in my game Il Duce's private Yacht)....
Yes I had that much spare IC and time to burn.
On that note HOI 3 is extremely mod able can't you just copy or delete a line in the relevant file to make it upgrade able?