Pirates! (I hate those filthy bandits.)

At the first, you caqn runaway, but later, you need to attack to get more crewmembers. Since the Midgame, when your logistic and your ressources is enough, go for the Pirates. That few energy cells you use is nothink for that what you get. More Crewmembers and also more ressources. You get more ressources then you spend for the energy cells.