(edited by Seldane.7845)
Basic Question about Deadeye WVW
On demand stealth combo and interrupts for D/P.
Mobility and AoE poison on shortbow with interrupt potential on the CG.
Main hand dagger offers cleave if the enemy is invisible.
Those three reasons are what those offhands offer.
D/P is good for dealing with people who are really sticky and will stay on top of you in melee range. On demand stealth.
Rifle abuses your power and range over the other player while providing escape functions.
You will also see Sword-dagger in the mix as it provides engage, disengage, boon-strip, evasion, and on-hit stealth.
These three sets work really well with malice. But only Rifle takes full advantage of the mechanic.