i am of the opinion that if you can protect against both then that would be better.
how about a very simple wire rope ring that can be fixed in place by spliting the ball joint off the hub carrier put the ring onto the hub carrier behind where the nut for the ball joint goes then re fit lower arm to hub carrier and slide the ring back over the end of the lower arm.
the ring wil now be round the hub carrier and lower arm and dropped into place behind the nut.
but then there is the movement issue again.