In the case of Yugoslavia, to take one example, there were three main groups: Croat Ustaze, the largely Serbian Chetniks, and the Titoites, who were largely drawn "neither of the above." These groups were respectively, pro-Axis, on-and -off, and anti-Axis. They were identified by their leaders and ethnic groups.
Soviets did collaborate with the Germans. At Stalingrad, something like one=quarter of the 6th Army was made of "Hiwis" (willing to help), mostly in support roles. And a number of men joined the pro- German "Liberation" army of Vlasov.
Were many of these people's actions influenced by ideology and ethnicity as in the case of the Yugoslavs? Or was it more a matter of "circumstance," e.g. most of these men were prisoners of war, who understandably want to escape their fate?
If I were to use a "Yugoslav" model to explain Soviet collaboration, my hypothesis would be that the further west a soldier came from, the more likely he was to be a collaborator. But it seems to me that "functional" factors such as POW status counted for much more. Is this right or wrong?