I don't agree
First off Russia and Germany did go at each other like Kilkenny cats, and it had nothing to do with America.
Second Russia and Britain would certainly have been allies.
Third, if Britain and Russia managed to defeat Germany, it would have been after a war that was more protracted and debilitating for Russia than WWII actually was. Likely it would have been years longer and included nuclear weapons. It is *not* clear that Russia would have escaped from that war in the position (dominating eastern Europe) that it actually did.