Someone explain 2man Mournfang units

I have only ever ran 4 man units with & without Dragonhide Banner.  So how would 2man units help me in an agressive MMU list?

Small frontage, still hit pretty hard and with a 2+ armour, 6+ parry they're a pain to shift.  Gives you another highly mobile threat.  I've often used them as well to intercept charges or as redirectors.

Another good thing about 2-packs is that if you equip them with great weapons they're pretty handy at monster-hunting. But as hmjesus said, they have the small frontage which makes them more maneuverable, and if you run enough 2-packs (like 3) and some other cannon-targets, you begin creating target saturation, which helps out some of our other stuff. Or, heck, run 2 2-packs and one 4-pack with the Dragonhide banner. Nice rounds of heavy cav everywhere

They are cheap and durable. It changes their role a little, but that is why you do it. It changes them from primary combat unit to chaff hunter and support charge. I really like running them as groups of two because it increases the chance that you can charge something you want.

Also, I don't worry about losing so many points in one go to waywatchers or searing doom.

I find they get ignored more as they are considered less of a threat, this makes it easy to set up flanks.