New Warrior Gearing - Green

[Azeam]

This may seem like a silly question but when I duel wield I have:

Silvery War Axe: 6 / 22
Gloomwater Harpoon: 9 / 31

My natural instinct is to equip the war axe primary and the harpoon secondary. but I've switched them up and appear to do more dps with the harpoon wielded primary, the thing hits like a truck compared to the war axe. Is there really that much of a difference one way or the other? Im not entirely sure of the mechanics of duel wield.

And another question for those who can help. I want to remember (going back 20years) there's a damage cap because my Langseax of the Wolves hits for max 31 at the moment, I'm 17. But I cant remember what level that damage cap comes off. Thanks!