The current battle system mainly calculate everything from Your Rank vs Mob Rank

[Reika]

ok heres really numbers

surf eft level 42 pug level 58 eft
dlevel 16

damage with weathered hora heavy strike 18-20
damage with level 39 boarskin cesti hevey strike 50-54

level 42 pug, level 61 biast
damage with weathered hora heavy strike 14-16
damage with boarskin cesti 25-26

so yeah attack does matter, but it had no effect when you fought the nm..... hmmm COULD IT BE THE NM AND NOT THE DLEVEL OHHHH SNAP THATS CRAZY TALK

Then there was the lancer in my party with the wethered spear. I was upset that she was doing close to equal damage as me >.> apparently that person was also testing it out too.
And I believe it is the closer you get to the targets rank, the less your weapon matters. which goes back to Rank vs Rank having too much of a role in the end judgment.