Investors interested in stocks from the Diversified Operations sector have probably already heard of Sumitomo Corp. (SSUMY) and Federal Signal (FSS) . But which of these two stocks presents investors with the better value opportunity right now? Let's 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 Zacks Rank favors stocks ...