They are doing nothing but sitting in the lounge so why do they get paid? Seems kind of stupid to me, if they want to take their unearned money then they should slowly accrue combat rank.
Because they are on stand-by, you hire them exclusively. Why would they accrue combat rank when inactive, they are only fighting the possiblity of bottom sweat, which is what get when your on stand-by.
If you think of your crew as someone who becomes a partner in your business instead of an employee, it makes more sense that they get a fixed cut of your profits.