I think that removing damage bonus from Huntsman ult will make him balanced.
But that will look dumb, so my idea is that his ult should stand to its name - ambush. I think its main purpose must be repositioning.
So the idea is - remove FOV decrease, remove movespeed reduction, remove damage bonus, allow moving through units, increase duration to 5-10 seconds, reduce cd. When leaving stealth, the first shot or hit should always be critical (and might have smth like 1.5x multiplier too) and for 3-5 seconds after leaving stealth Huntsman receives a reload speed buff and wastes no ammo when shooting.
That looks just like ambush to me. Damage buff and stealth are separated and it’s mostly used to repositioning. It also doesn’t buff Bow’s damage, that’s already crazy, but helps dealing consistent damage with slower weapons, that need reload.