You're 1 patch too late 😕 Teeing it up with a Cloaked Dizzy is a great way. Dizzy's burst just got nerfed though, and it's harder to get Minor Berserk reliably with a melee NB build (unless you sacrifice 2 pieces). The build is still decent though.

The main issue is that any decent player will just block or dodge the Onslaught unless they're CCd. So you really want use a hard CC on the GCD just before Onslaught, otherwise there is a very high chance you'll waste it (unless you're just mashing noobs). Dizzy works well because you can Onslaught them before they can break out of the knock back. The issue with Camo Hunter is that if you proc it from range before you go in to Onslaught, you'll give them CC immunity and then if they're half decent, they'll block or dodge the Onslaught. To proc Camo Hunter from melee range, you have to be directly behind them, so that your crouch technically isn't broken (this is extremely unreliable). Even if you're Cloaked, when in front or to the side of your target you're no longer technically crouched, so you won't proc the buff. This is why Slimecraw can be a good idea now and why the build was so much better vs good players last patch.

You can still actually do a combo with front bar Camo Hunter, where you fire a crouched back bar bow shot at a secondary target, switch to front bar as the arrow hits to proc the buff, switch back to your back bar and Cloak as you're running in, switch back to your front bar, Dizzy > LA > Onslaught the primary target. This combo is an absolute b**** to do though, which takes the fun out of it a bit and makes it way more unreliable.

You can still do what the guy above does, and hit them with part 1 of a combo, wait for their CC immunity to run out, then fear and Onslaught. It's not an instant 1shot but that's OK.

If you're looking to maximize your onslaught for better chances at one shots, 1 balorgh 1 kena or veli is better than 2x balorgh, and will slightly outperform 2x slimecraw when you factor in your weapon damage buffs (major brutality, medium armor agility passive, weapon damage buff in stealth.)

Khajit nightblade
Shadow mundus
All divines
1 kena, 1 balorgh
5 sword singer
5 archers mind
Nirhoned 2 handed sword

If you don't want to do it truly coming out of nowhere, use master bow back bar and clever alchemist instead of sword singer. But then you need to be in combat and use poison inject which kind of removes the gank element.

If you want just to get an insane tooltip on your onslaught:

Orc warden
Warrior mundus
1 kena, 1 balorgh
5 Sword singer
5 automaton
Nirhoned 2 handed sword
Slot all 5 animal companion abilities on your 2h bar. Each one will give 3% bonus damage and you'll get minor berserk. Not a realistic build at all though. And if you want to use proc sets, ravager and clever alchemist.