The French Foreign Legion is an elite force, open to non french individuals to enlist.
Because it is, by nature, a multicultural force, the legion has a specific trainning regime to develop unit spirit. These are not cannon fodder: any individual that can make the FFL, can after three years of service request french citizenship.
Russia seems to be just trying to find bodies to fill the ranks.
They accomplish that and the already diminutive presence they have in the world will shrink even more.