ZombieFall Question

How does Crit work with the new Zombie Fall gem?
Since it deals damage based on "2.5x the damage of a regular zombie melee attack", is it purely only the zombies melee crit chance?
So only the Fearsome Force wheel (looking at just the passive tree) affects the crit chance?
This might be old info based on the age of some of the threads I pulled online, but it seems they have a base 5% crit.

Or does my crit chance/multi/power charges/etc affect crits on the gem too?

It's a minion.
Since when have your crit chance, multi etc affected your minions?

I have played minions like twice haha. But guess that answers that question. Thanks