Muslim Slavs? WTF?
Shitler exterminated only the Christian Slavs (Russians, Ukrainians, Poles, Serbs, Slovaks.etc). The Muslim Slavs (Bosnians, Goranis.etc) either sided with the Nazis or stayed neutral. And your assumption that most of the Slavs were killed on the battle front is plain wrong. For example, less than 40% of the Soviet casualties occurred in the battlefront. The remaining 60% of the deaths were civilians and POWs, exterminated by the Nazis through starvation, mass-shooting.etc.
Christians were the only demographics not victimized by Hitler