Dual wield katanas vs jump attack?

New player here so sorry if this is basic stuff... I'm doing a samurai build and currently have two uchis (main hand +6, off hand unlevelled). I'm playing around with dual attack but it seems to do less damage than a jump attack using just my mainhand. Is this right? If so, is dual wielding worth it or should I just stick with my uch/buckler combo for parry?

Also, I'm still in the land of reeds armour at level 40, is it worth seeking out some new samurai armour?