Multicrew is a core game mechanic, not a Horizon's exclusive, there's a lot of confusion on this subject and FD has addressed it in the live streams but so many people don't watch those.
And who cares if you get a PvP advantage? If you are an Anaconda and a player in a Sidewinder attacks you, is that a fair fight? PvP is NOT the basis of this game, it's NOT part of the design specs, they don't worry about that because this is a single player game that you play online and you CAN allow others to join you or not. PvP is simply not prohibited from happening, it is otherwise ignored. How do people totally miss that when they look at Elite Dangerous? The Dangerous is not a reference to PvP, it's a reference to the fact that the game is unforgiving and the universe is a big, cold empty place where bad things can happen, that's all it refers to. Per FD, PvP is supposed to be a RARE event, it's not supposed to happen much, so it's not part of the game design, it's just NOT prohibited. You want PvP, play CQC, it's designed for that, still suffers some of the same non-PvP design issues but they artificially balance those out somewhat, but the Sidey isn't a match for the Condor or Eagle even so, still fun however, and unlike the main game, the PvP isn't a bad joke.