Apologies if this question would be more fit for r/HistoryWhatIf—I'm expecting higher-quality answers here is all, and I'm particularly interested in the legal considerations of my question.
The question's a fairly simple one—couldn't have the legal grey area Russia was put in as a result of being both a seceding member of the USSR as well as the Union's sole successor been avoided by naming the Commonwealth of Independent States, explicitly stated to be the successor organisation to the Soviet Union in the Belovezh Accords, the inheritor of Soviet Union's place within the UN Security Council instead of Russia? If not, why?
I wrote about why Russia ended up with the UN Security Council seat here.
In short: the Belovezha Accords were replaced on December 21, 1991 by the Alma-Ata Protocol, which recognized Russia as the legal successor to the USSR, and its claim to the UN seat, Soviet strategic nuclear weapons, and Soviet foreign debt. The other UN Security Council members were arguably anxious to have Russia assume the seat because there isn't actually a clear process in the UN Charter for replacing a Permanent UNSC member that doesn't exist any more, and they wanted to avoid a potential UN constitutional crisis.
As for the Commonwealth of Independent States, it was a very loose international organization that wasn't formally organized until January 1993, so effectively trying to give it the UN Security Council seat would mean giving a seat to an international organization which didn't even have any sort of institutional framework yet.