I knew from the faction description on the blog, but I did not think of them as all that dangerous until I saw a berserker get in a kill against some militia that had gotten ahead of my mercenaries. Then he got another. And another. And another. And another. Full swing, no survivors. Next turn he reached my company, killed most of them in the first round and the rest in the second. After that, I made them priority targets for my ranged units.
You can kind of think of them as the Orcish equivalent of swordmasters, in that they’re not a big deal if you just shoot them. However, if they manage to get in a good position they can really RIP and TEAR.