General Nedich was indeed an obedient collaborator, and didn't have much choice, given that Serbia was occupied by the Germans. Croatia on the other hand, was independent, and more than willing not only to send its Jewish population to Germany, but to "help" its alliy Adolf Hitler by setting up its own version of conz camps. I think there is a slight difference here.
Got to keep that perspective clear Trop. You can't draw parity between an occupied German-controlled Serbia and an independent, willing Nazi ally Croatia.