Magic Arrow wastes ataka because it triggers damage every 0.5 sec, so if you crit on that interval, your ataka goes on cooldown. It’s a waste because Magic Arrow has low SFR and is often used for the silence attribute.
Ataka on Bow is good for Bodkin Point, and then Barbed Arrow and Spread Shot, these are fake multhits, so you’d see 10m ataka damage most of the time, for homing arrow and zenith, you can see 6m-10m ataka depending on what you’re attacking provided you have +3 boruta seal.
And don’t compare yourself with BB, on my server, only Musk-TH could compare with BB or Dragoon/Lancer for Single target damage.
Regarding CM7, all my mergen skills are doing well, Cross Fire does decent output as well, although just a reminder I have them at max attribute and enhance arts. I also have a separate AoE Attack ratio set.
What this build does well at imo, is bernice and CM, sadly the rewards aren’t as good as getting the top WBR charts so you see a lot of archers switching to Musk-TH variants now.