Replace the stun affix with a knockback on hit legendary affix. Stun is useful but knockback would be stronger and more fitting for Marksman's bow, since the whole point is keeping enemies away from you to deal crits.
#Legendary Marksmans bow change
onyx quiver
boreal hare
Gilded Yumi moment
onyx quiver
Gilded Yumi moment
That thing is on a whole other level
boreal hare
Imagine Yumi with Marksman’s speed and ammo count 
onyx quiver
It doesn't even need it with how it decimates enemies