If you did notice, lvl 5 vs lvl 15 is a diference of 46% damage, this is only considering the base damage, and not the % damage. As you level up, this 46% goes down, the lowest diference to be registered up to this moment is 28%, but this was tested by iDream, his gear was not top tier, so you get the idea of what happens at high levels of gear.
And how would you build a Archer 2 Ranger 3 Rogue 1 X build?
The last slot needs to be occupied by something decent. If cannoneer, it is advised to get falconeer. If SR, you need to be SR2 to make it work. If musketeer, oh well, musketeer is kinda bad imo, but it would fit well in this build. Scout 1 sucks ass for a 7 rank pick and so does sapper 2. Wugushi asks for c2 at least. Archer c3 is bad. Hunter is bad due to pet mechs. Going past rogue 1 is terrible. QS asks for c3.
At the very least, you would go Archer 2 Ranger 2 Rogue A B. But at rank 4, archer 3, scout 1 and wugushi 1 are better options that do offer more damage. And ranger 2 is whack anyways.