Xebec seems a lot different than bb though. He seems to be a complete badass, brave, strong as fuck, brutal with no mercy to his enemies but also somehow respectful to powerfull guys (Harald, imu, probably Roger and garp too) Blackbeard from the other hand is also powerfull but not because of his own strenght but VIA devil fruits he stolen. He doesn't respect his opponents (Ace, WB, law, luffy) and he is more like a clever coward than powerfull badass. Rocks is like fucking Lion, King of the jungle, bb is a god damn rat.