Well, even though I just starting playing it, I would urge caution... from a statistical viewpoint, a "sample set" of only 2 is insignificant.
Oh, I'm not talking about throwing out the entire naval tree and starting over from scratch.
In fact, I'm not changing a single combat value of any of the naval units in my mod. What I'm going to do is make it "slightly less likely" that a more modern vessel will succomb to an older generation vessel, and I'm going to emphasize the roles of some ships.
I actually got the idea from the on-going conversation in the Frigates/Destroyers thread and recalled something similar in the older mod for Warlords.
It's mostly an "under the hood" change. Not one combat value has changed, not one price has changed, not one unit has been added or deleted. I'm just breaking-down the naval combat category (which is currently HUGE) into smaller (more measurable) pieces so I can be more precise in choosing which ships get bonuses against which ships. The main differance would be in the Civilopedia where instead of a Frigate being listed as a "Naval Unit" it would now be listed as an "Age of Sail Unit" and an Ironclad being listed as an "Age of Steam Unit"... etc, etc. Is that bad? The end-purpose for this is that now a Pre-Dreadnought age unit can get a bonus against Age of Sail and Age of Steam units without getting a bonus against other Pre-Dreadnought ships or vessels of more modern ages. It allows me to make for more accurate naval combat results, without having to resort to 120-strength battleships. All base combat values are staying the same.
Here's the end gameplay result of the above changes...
All ships from previous Wolfshanze Mods are unchanged in tech requirements, cost, look, combat value, etc, etc.
Ships will still function as you expect they would... a Frigate will do it's job against other age of sail vessels as it always had... it will also more then likely lose to ships of more modern ages... especially those ages two or three generations ahead in naval technology, though it will have a decent chance of sinking a vessel only one generation ahead (still an uphill battle, but doable).
Ships of more modern ages will still fight similar-aged ships in the same manner they always have... no differance there either.
The change you may notice....
Ships one or two (or more) naval generations in technology over a much older ship (say a pre-dreadnought against an age of sail ship, or a modern naval vessel against a pre-dreadnought) will sink a much older generation ship more often then not and/or take less damage in the attack.
In v2.3 and before, say a Dreadnought attacked an Ironclad Cruiser... you'd probably sink the Ironclad Cruiser, but had maybe a 50% chance of taking serious damage in-so doing (losing half strength or more) to a clearly inferior ship, even worse, you might have a 1-in-10 chance of being sunk yourself by attacking a clearly outdated ship.
In the new version in the same situation, you'll almost certainly sink the Ironclad Cruiser with your Dreadnought, and probably take less damage as a result of the attack... your odds of being destroyed in-turn will also drop, though it will still be a possibility you may be sunk (yeah, you can still "strike a reef", but it will happen less often with such disparities in technology).
Once again... these are mostly "under the hood" changes. Naval progression is the same as it's been in the Wolfshanze Mod... things will still make sense with historical tie-ins. No units have been added or deleted... heck, even the combat values remain unchanged. I'm just tweaking it so a nation/civ that has a technological naval advantage is more then likely going to dominate the sea over a nation with less naval technology... as it should be. Somebody with a WWII Sub shouldn't be afraid to lose his sub when attacking an 1860s Ironclad Cruiser. However, it's not a HUGE/DRASTIC change... nothing is automatic or assured... the chance that sub's torpedoes will go afoul and circle around to destroy the firing sub are still there... the odds are just a little less then they were before. That should make the Civ-purist happy.
P.S.
I can assure you... every one of my new naval categories in the Wolfshanze Mod will contain more units then the default Civ4 "Helicopter" unit category that Firaxis themselves put into the game. So if you're worried the Wolfshanze Mod will be strange for the number of units in a combat category, fear-not... I have more in my categories then Firaxis has in theirs.