Textures, dear modelers.
They make the ships look like they're from the same faction.
But don't look at the gunboat to get a sense of hessian cap style.
Look at the fighters.
The gunboat isn't actually pretty - sorry to the modeller - but it's ewww.
It's also horrible in PvP, but this set aside it still isn't fitting for hessians and should be redone too.
Should the battleship look like the cruiser, just in big? No. The cruiser looks good as it is.
The battleship looks good as it is too.
Another thing ... the engine-effects should be similar.
EDIT:
I also like the slight resemblance of the Rheinland BS in this BS.
But as I said, the engines aren't that fitting for a Rheinlandish Hessian Battleship in my opinion.