Apples and oranges. 2% of a military unit, as with the FFL forces you describe as being "muslim," is a tiny fraction. With the German officers included, the jihadi SS units would've been somewhere in the 99% muslim range.
Apples and oranges again. 20,000 of approx. 18 million is a tiny fraction of the overall troop strength. Whereas Muslims constituted a plurality of the FFL's African troops, a group that was itself a significant portion of the FFL.