Honestly, just no.
The merchantman would never have insane armour etc, its going to lose to a frigate unless that merchantman is insanely good and the frigate is insanely bad.
People always gravitate to the optimal thing as this is how life works. Natural selection, schedules, you name it, they all move towards the optimum.
In reality the victory and santisma and any big gun ship WAS bad at sailing, its not some made up number its reality. You stick a massive wooden platform weighed down by 100 guns it will sail poorly.
Your points system doesn't make sense in a open world game, this isn't basketball or some other sport.. you win or you lose the battle, and your ship, and a point modifier has nothing to do with it.. France and Spain didn't win at Trafalgar on points because they lost the battle but were outclassed by the British skill. See the logic?
Please don't use MWO as a reference, its a terrible game and most people agree its terrible. Its also a arena game with no MMO aspects. Apples to oranges.