In fact, almost every chapter (as Deep said) inducts their failed recruits into the chapter cult. Chapter serfs, or whatever, are a vital part of every chapter. So what if these guys call them "troopers" or whatever. The DA even go so far as using xenos who seem to be native to The Rock. Hell, even the Adeptus Ministorum can raise a mostly-male Frateris Militia despite the injunction against having "men under arms."
"You fought with Captain Reynolds in the war?"
"I fought with a lot of people in the war."
"And your husband?"
"I fight with him sometimes, too."