Full realistic isn't fun. A lot of things can be on the realisitic side, but you still need balance and fun gameplay. Nobody is saying a row boat has to be as powerful as the Constitution though. But if a guy is AFK at sea, why shouldn't a ship with cannons not be able to just park next to him and fire shots into the lower end of his hull? If you want a big, reliable community you need a balance of the two. Create the feeling that you are sailing a real ship, on the real ocean with a lot of risks and stuff is fun. If they go the route of factions, or anything that locks you into a side it should be balanced.
Look at any game, and people always swarm the OP stuff.