Hmm, I know there are skills that give them adrenaline at the start of each fight but it's like 30 for all five stacks or so if I remember correctly? So it's 6 each? Doesn't seem much when their best abilities need 3rd level of adrenaline.
I guess I find the concept of adrenaline annonying because it's the start of a battle when you need your most powerful abilities and bonuses, not the end when you just mop up. It seems they're designed to build up and become extremely powerful - in the 4th round
So they'd be fantastic in those five or six key battles that last more than 3 rounds.
But ok, I'll try them for my next Skald playthrough and see.