Honestly I play with crit dmg set on 2 toons in my arena team. If I would have more good speed secondaries on crit dmg mods everyone would have full crit dmg set. It is changing a lot fights in arena. With speed set I have to take more turns to win. With crit dmg first toon is dead in one turn. I play Empire switching beetwen Thrawn or Palp as a leader so my team is having many turns from tm gain. Vader for example doesnt need speed set and speed as a primary on arrow. Against CLS under Palp, Vader always goes first with 60speed from mods, against Palp team, Thrawn lead gives so much tm that whole team goes after opponent's Vader.