Pirate101 PvP Combat in its current state is one that lacks the polish of a full blown PvP system. Perhaps this open letter about Pirate101's simple PvP system will answer more of your questions.
In particular, "All PvP matches will be set up to be Epic Battles – meaning that players will choose the companions that they bring into the fight. This was done for a couple of reasons: one, to make the fights less random, and two, to make sure that crowns-purchased companions were no more impactful than quest-granted companions. (If everyone can bring in their best three companions, then it doesn’t matter if you buy twenty great companions, or none – everyone can bring their three best, and therefore everyone starts on equal footing.)"