I would agree with you, but then I checked Yvain's stats. Given how he just joined it wouldn't make sense to completely remake him off the bat but... He can be doubled by all but two enemy types. Three if you include the caravans (maybe). He definitely needs more spit and polish than Kaarina at the moment. Though honestly she isn't that far in front of him. Right now Ociel the Troubadour is slightly better than her due to all of the axe-wielding enemies in the mission and I don't expect the gap to close after a few levels. However a +15 Hit or +10Hit/Eva PS will fix most of Kaarina's problems and she has the Double Axe to compensate with in the meantime, so I don't mind. She should turn out fine in the end.
Also after doing a lot of number-crunching, Vandertz seems to be better in combat than Lycan whenever he can double an enemy. The extra damage definitely makes up for his lower hit-rate. However Lycan's Pilums allows him to double any enemy so he obviously does better against those that Vandertz doesn't have enough speed to double. Mostly the Heros, Snipers and Assassins that are running around. Also Katerina is deadlier than I thought she'd be. The rework was obviously worth it for her, since she's pretty much on par with Aura at the moment in terms of combat power. Kat's extra damage is balanced out by the her lower accuracy, so they're more or less equal at their current levels. Though Aura can automatically hit most enemies if her PS applies so that's something to consider in the future. Only the Snipers and Assassins have a small chance of dodging in that case, though everyone has trouble against them so she gets a pass.
After a couple hours of crunching numbers and theorycrafting I feel like I should roughly rank the characters in terms of combat prowess, but I feel like that would go over like a wet blanket with everyone. Fighting over who is stronger than whom doesn't seem like a great way to play the game.