Not really sure what the problem here is, sorry.
Do you believe that the computer uses the Player's Combat Tactic selection to select its own and so automatically has an advantage in all naval combat? I will admit to not keeping detailed records or analysis as to all the potential modifiers and outcomes in naval combats and to be honest, am not entirely sure that it matters a whole lot. Like land combats, the Naval Tactics selection process contains no absolutely correct or one-size-fits-all solutions and if it is not working according to design, I have never noticed it.
Naval combats tend to be attrition heavy, expensive and seldom decisive and this is pretty much in accordance with the record. Modifying and eliminating the Royal Navy's offensive and defensive handicaps in the stock game (which make the RN by far the least effective and most vulnerable combat fleet in the world) goes a long way towards facilitating a reasonable outcome. That said I am unable to determine why the combat tactics selection might be a significant issue.
Perhaps I am missing something or otherwise cannot understand why you think this a broken.