One of the arguments by those who like Walter S. Dunn, Jr. argue that a second front in France "was not only possible in 1943 but advantageous to the West"
https://books.google.com/books?id=xeu3DAAAQBAJ&pg=PA205 is that it would let British and American troops meet the Red Army at a point much further east than in OTL. Indeed, Dunn suggests that after Stalingrad "It is likely that Stalin did not want a second front in 1943, at least not in France.
He feared that U.S. and British forces would not only sweep aside the weak German forces and occupy most of Germany but perhaps even parts of Poland, while the Russians were still fighting east of the Dnieper River. Because he was aware of the political risk of an early collapse of the Germans in the west in 1943, he supported the diversions to Sicily and Italy." Of course it is arguable that Dunn is far too optimistic about the chances of success of a Second Front in France in 1943; we have debated this here before and I don't want to get into it again.
BTW, I agree that the Soviet occupation was brutal, most notoriously the rapes of German women ("Frau, komm"), but I would not equate it as the OP seems to do with the mass extermination of peoples the Germans resorted to in the USSR. See
https://books.google.com/books?id=KfXXAAAAQBAJ&pg=PA150