I'm not convinced this is good in any but pub games honestly. I tried a few games with this build and I was not satisfied on a couple of points.

Firstly, you don't require 3 health potions in the jungle, you only really need the 1. And if you are generous you could by a stealth ward and ward river near mid. Secondly, i'm surprised you don't take the skuttle after blue/red it spawns at the 2:30min mark and is easily acquirable if you are good at managing the bug (It also provides very useful sight of the river to prevent ganks, as you are unable to gank well till 6).

At roughly 7:30-8:30 minutes you should be level 6 and ready to gank. You don't require the devourer to gank, full stop. If you had leveled your Q you could initiate with your ult+smite and then Q to finish them off (with the help of the laner). So your build is weaker at lower levels it seems as you are unable to gank and provide a meaningful impact early which arguably is one of the biggest problems for WW.

Also as a final note, there is very little in the way of armor/mmr etc in this kit.