It seems so. And if you hit more than one, whichever ones your attack lands on will join in.

[He'd struck it full on with the intent to see how it reacted to his blow. The second time he attacked had been to check if the effect applied to all of them.]

I'm not sure if that applies to swings or kicks that go too wide. I was intentional when I hit more than one. ...I can't tell you how hard they hit a normal person.

Both times I actively fought them I wasn't in human shape.