While the troops of the EMM could be described as having been "pushed" into the organization to prove their loyalty to the Union, those who served in the PEMM could be described as having met that test with flying colors. As a rule, the troops of the PEMM were hand-picked Radical Unionists--i.e., they were staunch Unionists, in the extreme.
Questions on the EMM and PEMM crop up on this board two or three times a year. Unfortunately, there isn't much out there. You can go to this link to find out a little bit of information--
www.civilwarstlouis.com/militia/federalmilitia.htm