Manually managing salaries never saved a company. It pushed several to their doom, OTOH.
Manually managing hires/fire is less dangerous. Need changes only when planes in operation change, and that's plain clear. Mistakes are possible, but easy to correct, and not THAT dangerous. I don't do because the potential profit is ridiculously low, yet I'm not shocked by players who do. But manually managing salaries is a false "good idea".