Greedo is a great damage dealer but is too streaky to be relied on in arena. Useful for raids where you an restart or when you Really need to roll dice (like Chewie event).
Cad or Embo are better for pvp. Cad offers more control because he has a stun. Embo can just straight instagib 2 characters back to back with massive damage. 50-70k hat throw + 30-40k kick that ignores protection can kill 2 attackers/supports in a row under right circumstances. Both Cad and Embo have more survivability because of Cads dodge and Embos no crit+foresight.