If not, why does my Berserker have Highlanders face?
No no no. Your Zerker is just very clearly homeless and may or may not be using a few substances they should not be using. It's probably because serial killer Raider burned down his house. Just look at his new outfit, no normal warrior would wear that.
He looks like he's aged about 30 years. I swear that's one of Highlanders helms. Look at the thumbnail. It's Highlander!
Somehow, I think he looks even older than the Highlander. I always pictured the Berserkers as younger people than Warlord and Raider...