The triangular shape is the problem, though. It makes the ship fat, and the bridge makes it tall. Length is irrelevant compared to width and height. If it could be narrowed down or flattened, then it would be balanceable as a medium battleship.
Although this version is even more eye pleasing than the current Sarissa, it doesn't solve the very problem it is being remodeled for. At least I think it's being remodeled because it's unbalanceable.
To change the general shape is, according to that, not something you aren't supposed to do, but the very opposite.