Idea, merge Sea Dogs and Pirates, move rebels to the faction that leads a rebellion against the pirates who've imprisoned them, and make a faction called The Resistance or something that fights the Armed Assasins.
Rebels could consist of -
Spyder (Jak Goggles)
Desert /Golden Abyss Drake (Bandanna Mask)
2 Custom Heroes
Resistance would wear stuff like Mountain Jackets, ISA Helmets, looking more like a military than the Rebels, I wouldn't want them looking the same.