One thing I noticed is some people said it would have to be non-Nazis but since the OP states that was already conceded. In any case I think it is doable particularly if the goal were to make the Ukraine a German-Polish Protectorate. Ally with the Poles and then make a deal where the Ukraine is largely autonomous but has to provide troops and tax money for protection.
Poland would indeed make a good ally for an anti-Bolshevism crusade. Almost too good of an ally, since if they win, Poland has destroyed a major threat on the eastern border and created a bunch of satellite states which would include at least Ukraine and Belarus and probably Crimea and a Cossack Nation/"Cossackia" (no need to strengthen Ukraine too much). If they get far enough, they can sever the southern Caucasus off from the USSR, which Poland had great interest in. Not sure what territorial concessions Poland might grab.
So the question becomes--what does Germany get out of this? Can they get Poland to give back the desired German lands in exchange for all this help (maybe involving a population exchange/ethnic cleansing where ethnic Poles are resettled in non-Polish areas in the east and Ukrainians expelled)? If not, then it would be a hard sell to the German people and leadership.