Update: I have discovered something. Frigates have been made unrealistically powerful since the last patch. Prior to the latest patch, Ships of the Line could easily defeat a fleet of frigates. This is no longer the case. I have been defeated twice by fleets of around 12 frigates. I have decided to make a rule limiting frigates or smaller ships to a max of 4. i have played around 4 or 5 naval battles with these rules and found the rule balanced. My fleet now consists of 6 ships of the line and 4 6th rate frigates.