For sure the 3rd picture I have was worn by Marines. At least initially. I have pictures of them on parade in this type, which is obviously different from the one in the 4th picture.
At the moment I am considering the 3rd picture to be Navy/Marines, the 4th picture to be Army (GOE to start, but probably others now). No 1st or 2nd model designation since they apparently were both produced for different users.