Actually, for 2H, there is some kind of "balance" : 2H sword has higher dps than Maul, and hits several targets. Maul DPS is a but lower, is single target BUT has slots. In the end it makes Maul much preferable IMO, especially with level 3 mods, but clearly there was some reflexion behind this.
DPS stat in weapons does not matter, it only shows "dps" of auto attack chain. Abilities are based on base damage of weapons. Because of that maul will always win.
Also let's compare those two using my versions:
2h sword - dps displayed 362
+41% attack
+8% hok
+7% crit chance
base damage 295
Maul dps displayed 359
29% attack
+11% hok
+ 36% crit damage
+ 9% crit chance
base damage - 330, stats with upgrades of course (probably highest damage upgrades)
36% crit damage is way more than 12% attack, it's obvious I will say. Next more crt chance and more heal on kill. So stats wise hammer wins.
Next is base damage, vital for every ability calculations.
295 vs 330 ~12% damage difference.
So we have 12% damage difference from base damage + better stats. There is no reason to use 2h sword over maul at all.
You can say that hammer lack of aoe on autoattack and in general clunky animation would make 2h sword look better. But
Avvar, Reaver don't use autoattck at all, they purely use skills. Exception could be katari, as a 2h class with highest ratio of using auto attack but you can just use whirlwind and still boosted damage on charge, mighty blow and other skills is worth taking a hammer. Damage difference depends on promotions and stats but in general I can say it's something between 12%-25%.
What is also important you can upgrade maul with crit chance or heal on kill and still it will be better, just because of huge base damage difference.