It doesn't actually wobble in the way we think about loose fits wobbling. The centerline of rotation for the tools is at an angle to the centerline of rotation of the lathe. Since they're both rotating together once the tool contacts the work, it means that each corner of the broach contacts the work in turn essentially nibbling out the shape. That means that the broach tool then needs to have a back clearance of the offset angle plus a little.
Originally Posted by IOWOLF
Since they have the angular CL they also need a means to be set transversely a little to line the broach up with the hole center for tools of different lengths.
I've seen them made in a home shop kind of like a live center, but with a toolholder cavity instead of the 60 degree plug.
"In theory there’s no difference between theory and practice. In practice there’s a lot of difference.” Yogi Berra