Actually, you specifically mentioned pilot slots when you said there wereOne doesn't join the guard for a "mechanic slot" or "supply clerk" slot. Those are called jobs.

As for your idea to join a guard unit to fly a desk just so you can hope to rub elbows with someone who can write you a letter sometime later down the road, well... That's a terrible idea and and poor use of ones time or energies. Attending a job fair would be far more beneficial networking event.