Actually, Hadley, that would make some sense...
If you notice that ops, tactical/security and engineering are all the same "branch" in the late-24th C. Starfleet, its clear that they are "technicians." That means that they're technical specialists, and their "basic maintenance" job description makes them suited to handling repairs to a variety of pieces of equipment. Junior enlisted, especially, are probably interchangeable between the three sections.
Davy Jones
"Frightened? My dear, you are looking at a man who has laughed in the face of death, sneered at doom, and chuckled at catastrophe! I was petrified."
-- The Wizard of Oz