Melee firestrike: Ulzuin or Justicar Set?

I see a lot of melee firestrike builds online use the justicar set, but I can’t see an advantage over the Ulzuin set other than armor and DA.

I am not saying that armor and DA are insignificant, but the Ulzuin set just appears to offer so much more.

Can someone tell a not-so-talented-theorycrafter like me, what the advantages/disadvantages to the two sets are?

+8% OA thehidden10charactersp

I just went 3/4 justice with the fire helm vs 4/5 ulzuins (w/o shotgun), and the Ulzuins definite gives about 300 more OA.

Oops sorry I had the wrong set in mind. My bad.

Edit: mixed up Judicator and Justicar