Investors looking for stocks in the Staffing Firms sector might want to consider either ManpowerGroup (MAN) or Robert Half (RHI) . But which of these two stocks offers value investors a better bang for their buck right now? We'll need to take a closer look.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The proven Zacks Rank emphasizes companies ...