While I've never had any trouble fighting elite level troops, I do have a lot of trouble finding them. In many cases I find more troops that are higher level than the quest's troops.

For example I find more Fighting Uruk Hai Champions compared to Fighting Uruk Hai Warriors, and during my quest to kill 19 Warriors, I probably have killed triple that number in Champions.

As of currently writing this post, I have the quest to kill 33 Goblin North Clan Skirmishers, but we have pushed Mt Gundabad's outposts to the point of Gundabad itself only left. This wouldn't be so much of a problem but the entire 700+ troop army has only 6 Skirmishers in them.

What I suggest, if possible to program, is for the Elite Troops to count a number of elite troops, such as instead of only Fighting Uruk Hai Warriors, it would be all of the Fighting Uruk Hai group of troops, so Fighting Uruk Hai Champions, Warriors, etc., would count towards the quest.