If it is so good, and offered a clear advantage, wouldn't the FBI and LE still be using it???
First, you are making an assumption that government entities do things because they make sense. Big Mistake. But you are correct that they are choosing 9mms, .40's and .45acp over the .357 and for them it probably makes sense. But again your assumption is they are doing it based on the effectiveness of the cartridge. Again, big mistake. It's 100% about platform not cartridge.
And you're assumption that the Marshall and Sanow's study ranked the .357 highly because of wide spead use is also bunk. Overall, their study is irrelevant and lacks enough samples to make the conclusions they arrived at but with your thinkin the .22lr should of also ranked high since they had so many cases where it was used.
Basically, you need to read less, shoot more.