The ironclad in the game (looking at the picture) represents the entire class of pre-dreadnought "battleships". Seriously, the picture looks just like the USS Maine, of Havana harbor explosion fame.
Coal is accurate, too. Actually, the HMS Dreadnought and (I believe) all dreadnoughts up to the Queen Elizabeth class were coal-fired.
And also of course, those ships were incredibly tough - an 1890 "ironclad" would handily stomp a WWII destroyer. Armor thick enough to shrug off an 1890 10" rifle isn't going to notice a WWII 5" round.
So. I modified them to upgrade to battleship. That, in and of itself, made them worth building. ummm... I also upgraded battleship and carrier speeds, they're a bit too slow in-game. But the killer was I also bumped the nuclear submarine speed waaay up, damn those things are mean now. Made them require uranium, though.
Regardless - after tweaking a few things I'd been thinking were "wrong", dang I'm having fun. TL;DR - don't like it, just tweak it a little yourself, no harm done. <shrug>