It’s not just that. The insane buff two handed weapons have got also plays a large part. A +16 tra10 varna two handed sword gets 12124-17166 atk, and barbarians can raise the minimum value by half of that, greatly increasing the average. A +16 tra10 ornament adds more than 2k phys attack to it, and easily gets to 2.5k phys attack with a gem (it doesn’t add much, but they were limited to 5 gems before). Even putting gems aside, we’re talking about 14308-19350 atk from weapon and ornament alone, or 17137-19350 atk for barbarians. So an average of 16829 or 18243 depending on the case. For comparison, a varna rapier +16 tra10 gets 12706 atk instead. As the attack formula uses the sheer physical attack in two places (either normal or multiplied by 1.5 when critting, with phys crit attack added just after) and in the logarithmic part (phys attack alone here) this alone creates a large inbalance between different weapon types.
Let’s take Misrus for an example, with 29652 def. I’ll use my own stats with the fencer build and rapier as a baseline, so around 22000 atk (a barbarian/doppel/blossom blader gets more str from the base build stats, by the way, so it would be slightly higher in their cases).
The logaritmic part ends up at around 0.2466. Considering no buff and no crit, it ends up as phys atk multiplied for the logaritmic part, for a total of 5425 (this would be eventually multiplied for the various skill factors and damage buffs). A two handed weapon would have around 4k more average attack, for a total of 26000. The same formula would result in a logarithm of 0.2761 and a total of 7178, 1.33 times better than the rapier, and that value gets further multiplied by the buffs and skill factors. A two handed weapon with barbarian attribute would have further attack, adding around 1400 atk on average, bringing the total to around 27400. The logarithm in this case is around 0.2858 and the total is 7832, so around 1.44 times compared to the rapier.example. Crits just further amplify the difference between weapon types, since phys attack is multiplied by 1.5 times in those cases. But you get the idea. It’s not like you can make up for such an high difference of sheer attack. And buffs like swell hands, working as a percentage of atk, further amplify the difference again.
Worse is that such a large attack buff was given to builds that already had inflated skill factors and additional damage buffs on top of it. It’s not surprising that it ended up so unbalanced.