May of been historical during the Seconds World War Croatia was a axis partner i.e junior and there were links between the Ustashi and SS.
There was even a Croatian legion fighting on the eastern front.
And the Bosnian Muslims were part of the Ustasha and they fought on the Eastern front with the Croats.
That's right. They got wiped out at Stalingrad ( I think ). The few survivors were given a choice. Take a one way ticket to Siberia or join a "Yugoslav unit" ( I can't recall the exact name of the unit. John Ericksons' book on the Eastern front details it ) and fight with the Soviets.