if you have a KM BB then you will only need the opration crew + sonarman &planesman
basiclly i will tell you what crews KM SS5 needs to make it a hunting shark and you should know about the lower tiers
1-BO most ss players make there BO ghost (no sailors)
some other players get elite repair and delay the classing as BO for very late level
and then make that sailor a BO with out making him a ghost cos that will give them good repair
2- two tropedo crews (torpedo stat 12 if possible if not 11 will do)
3 planesman 15 POT if possible if not try 14 (if you have olives buy Elite Potential Sailor)
4- sonarman / if you plan to be other SS players nightmare i suggest Elite Potential Sailor then Premium Sailor
if you just wanna have fun 15 or 14 POT will do it
5-two engenires with 12 engine stat
6- repairman with 12 repair stat
all of the above stat are good but you will need to BVE your crew to have the best out put from them