As far as the actual TP set goes, this is what I've got cooking for Difficult/Very Difficult battlefields.
ItemSet 317954
(Iuitl wristbands have Racc+7, I still need to upgrade the braccae to +1, and should have Elanid Belt sometime this week)
This set offers more than simply the ranged accuracy however; the enmity reduction is nearly the gear hardcap at -44%.
Nikia has seen this set in action more than a few times over the past week, and save for the fact that I'm using Namas exclusively for anything higher than a normal battlefield - it works out great.
Provided that you're dumping your CE onto the Pld for three solid minutes when decoy shot is up, then camouflaging for white damage exclusively once it's down (a strategy I've recommended to multiple Ajjub/Eminence JR Rngs), as long as you keep a solid head on where your damage/hate is at - you "shouldn't" have any problems enmity or accuracy wise. (*Minimal support I find necessary for difficult in this set should be at least NQ Sole, Hunter's Roll, or Archer's Prelude*)
The only issue that starts to occur is when the fight is lacking damage and drags out for longer than it should. Then, even using Namas is a gamble (10k CE/VE cap says "Hi").