Didn't they even have the formal requirement to officially be
not french when joining? Like french people pretended to be swiss in order to be able to join for some long time? Officers where in fact french forever but regular french army staff.
But why would a french guy not join the regular french forces right away and opt for the legion instead?
That's what they earn:
https://special-ops.org/72/salaries-...oreign-legion/