No, the guard is a check that deters burglars form taking advantage of you. After a burglary is too late to bring guards on board, and after dramatic unmerited changes in the terms of employment is too late to start a union -- or, at least, later than you'd like.
(Not commenting on whether the union will actually work as I've described, just trying to spec out what a reasonable union would look like here, and refute the idea that it's "doing nothing" when the union has a good deal that lasts.)
It's actually pretty invariably when unions are formed other than at firms in industries that are otherwise pervasively unionized.
Which is actually pretty analogous to physical security: outside of measures taken by everyone in similar circumstances, most heightened measures are taken after a dramatic experience shatters the sense of safety.