There are a number of possible "tweaks" that might make the situation more realistic . . .
i) each strength point of a battleship unit should equal 1 dreadnought - so not all battleship units would start the war at 10 points (e.g. Russia might have 2 battleship units of 4 strength points each, one in the Baltic and one in the Black Sea)
ii) and maybe the more recent pre-dreadnought battleship classes (1900-1905 approx) could be converted into battleship strength points at a ratio of 2:1 (so you would not need to create a new unit type). Older pre-dreadnoughts (before 1900) were more likely to be used for coastal defence (represented by green dot hexes) or for patrolling colonial waters so they would not be represented in the battleship unit (although they could be represented in the cruiser units perhaps).
iii) repairs should take longer for all ship types, not just battleships - so 1 strength point per turn could be the maximum repair possible
iv) the building of new battleships could be handled differently so that players would actually be building individual ships (represented by adding extra strength points) for their existing battle fleets instead of building whole new battle fleets from scratch. At the moment each strength point for a new battleship unit costs 8pp's - maybe the new cost might be 10PP's for each individual battleship.
v) the damage inflicted during combat needs to be modified so that units are not so easily completely destroyed. We need more ships being able to limp away from battles and returning to ports for repairs.
From what I am beginning to understand about modding and patching all these suggestions are probably moddable or patch-able too.
