I understood this as a past reference not future based on one article I read on Joel. In all areas of life we wander. Shepherding and being shepherded are daily events in our communal lives and probably something we don't intentionally study enough. Calling people together though in purpose is a powerful thing and can be both beneficial and divisive. Easier and better to be a good shepherd bringing strays back before it gets to the point where a large gathering must be called.