The way it works is that if a candidate is going on a CVW due to a sport (football, soccer, hockey, crew, etc.), that coach will match them with a plebe from that respective sports team.
If your candidate is going on a CVW that's not related to a sport, then what happens is that plebes from different companies just volunteer to take in a candidate for that weekend (or at least that's what my company did last year) so in that case it's completely random.
Hope that helps - 2017Mid