Ops flexibility. The augment crew can operate the next days pattern whilst the other crew return. Net result-less HOTAC and a reserve crew available in case of sickness-what good is an S/O who can't occupy an operating seat. 2 x CA/FO =2 x crew. 1 x CA/FO + 2 xS/O's = 1 crew.
Management material right there folks!
On the grand Scale of things ( recency, etc) second officers are cheap. But overtime paid as well? That's For another thread!
Ducking due Incoming
