if you add something like this .. the crew idea ..
then think about adding captain reputation .. better captains equals more prizes, equals more prize money, equals more crew for said captain.. perhaps cheaper crew .. or better crew .. or .. well .. take it from here..
Captain reputation .. based on ships sunk, ships captured, cargo looted, distant sailed, ports visited, cargo purchased .. gather all the info/stats .. base it on crew lost vs crew killed vs crew pressed ..