It helps to have Staff who specialize in 1 job. For example, Sales Manager who does both production and business deals get paid astronomically more then a Sales Manager that specializes in only production.
I believe with near max skill, the Sales Manager who does both jobs gets paid at least 300k while the specialized Sales Manager gets paid 120k. So it is cheaper to hire 2 and specialize them.
Also, spamming singles early on helps keep some cash flow, but it'll raise production skills quickly, in turn wages.