If it’s any consolation, those tactics don’t work in the aircraft/guided missile age either. In fact, it looks like the primary concern today is anti-submarine warfare, as it’s assumed any Task Force/Battle Group would easily overwhelm a convoy and it’s escorts.
In other words, in any game which is designed to represent a force on force engagement where both sides have the same combat potential, it doesn’t make sense to give one side some extra ships they need to protect. I’d suggest as a starting point is for the convoy defender to have twice as many points as the attacker, and have a fairly small point limit for the defender (800 in FSA). Also, big ships aren’t allowed for Defense, as logistically you can’t afford to put them on escort duty. If the attacker wants a lone Battleship roaming enemy shipping lanes, go for it.