Welcome to Librarium Online!
If you use this banner, which unit do you put it in?
I often see knights with this banner. But isn't warriors more reliable, as the knights, with the faster movement more likely will get into combat fast? That's my thoughts.
You should be looking at your army as a whole. Where do you see your banners fitting in to each role of your army.
An example with both warriors and knights in an army. I would put wrath on my warriors if I were using them as a bunker essentially as a unit that isn't likely going to get in combat, but is forcing the enemy to almost stay put using my knights as hammers with something like rage or warbanner.
An example taking my all calv army. I would put wrath on my unit of knights that acts almost in the same way as the warriors would in the above case while leaving my hammer knights with a hammering banner. A bunker for sorcs that get attention, but are not likely to get into combat unless the opportunity arises.
Let me know if this lacks clarity.