Firstly I would say that you can definitely drop your Haste right down - depending on your sims (more on that later).
I would imagine that you'll probably sim higher stacking Versatility > Crit.
Justiciars Vengeance is a big DPS loss - especially more without Divine Purpose to gift you procs. I'd suggest using it only in the most extreme circumstances or ideally drop it all together for Eye for an Eye. This is even more true if you've reached Echo of the Highlord on your artifact tree.
Templars Verdict should be doing at least 10% - 15% more of your overall damage.
Possibly consider Zeal over The Fires of Justice - again dependent on your sims.
Right now your haste is more than high enough so use Versatility or Crit food, Flask of Countless Armies and Potion of the Old War or Prolonged Power (cheaper) on the Crusade Zergfest. Enchant neck with Hidden Satyr (if you can afford it), and enchant rings.
If you have a WQ trink with Vers/Crit you may also see a benefit swapping that in. Icy Veins has a pretty accurate listing of trinkets
here.
I'd suggest running Vault of the Wardens Mythic for the Faulty Countermeasure Trinket and Darkheart Thicket/BRH for the Wrath of the Ashbringer relics.
Overall though I really recommend that first you get into the habit of simming your character using SimulationCraft
https://www.simulationcraft.org/. Also install the SimulationCraft addon from Curse.
Once you've downloaded and run the program > options > Scaling, Enable Scaling then select the stats you want to compare. The results will show you your stat weighting so you can see what to change. I'd also sim tweaks to talents to get your optimum spec and of course gear you want to swap in.
I'm about 4 ilvls higher than you and the above tips (from this forum and SimulationCraft) helped me immensely - you can see my logs a few posts back.