Flicker - Frenzy charge sustain?

How does this build generate enough frenzy charges? Is the corrupted flicker strike with 25% chance enough? I can't find anything else that generates.
It seems difficult.

https://poe.ninja/builds/mercenaries/character/Dimitrii-4208/KinomotoFlick?i=0&search=skills%3DFlicker%2BStrike

With their setup, they're probably just relying on Ancestral Fury with melee splash and strike skills target an additional enemy, which should sustain charges on packs just fine.

Not sure if that's good enough on its own to sustain charges on a single target though.