I'd forward the idea of an initial five-headed hydra of Voroshilov, Molotov, Mikoyan, Zhdanov and Beria and then, after the inevitable bloodbath and backstabbing, Beria gets killed, Voroshilov takes a powder and Kaganovich, Khrushchev, Malenkov and some utter nobody with a stolid Russian name fill out the cast to create an appearance of an even bigger council. In reality, Molotov would be the face of the regime with have more power than other, but after the war it'd be a race to the bottom between Khrushchev, Zhdanov and Malenkov and I got dibs on Nikita, just as in OTL. Here's my rationale:
Voroshilov on paper has the credentials and one would require a military man to look good in front of a poster at time of war. He gets in, but does nothing with it, or screws up so bad somewhere that he is given a chance to walk away.
Molotov has the highest rankings and has the name value. It is bad enough to lose Stalin the All Consuming at the start of the war, but now one needs to put the best foot forward and Molotov certainly had the most credibility. Also, in making my list, I weighed heavily towards survivors. And Molotov was a survivor.
That's how Mikoyan gets on this list. He is on the Politburo, he's the Foreign Trade guy and then there is the Baku 26. In the strange and confused history of Soviet occupation and local responses in the Caucasus the Baku 26 is a messy mystery. There were 26 Commissars in the Baku Commune in 1919, Mikoyan among them. When Baku was about to be overrun by British backed counter-Revolutionary forces, they fled, were captured and were executed. All of them, except one man. Mikoyan. How he survived is a mystery to this day. But the fact that he did, and that being the only man of a 26 men team who came home and was not accused (even at the height of paranoia) of selling out his comrades... Mikoyan gets on the list and lasts, quietly.
Zhdanov - the forgotten monster. Zhdanov was sent by Stalin to re-integrate Estonia in the loving bosom of the Soviet Union in 1940 and came back, blood dripping from elbows, to be his satrap in Leningrad during the siege. Zhdanov finds a seat at the table.
Beria - three years into his reign as newest Chekist and momentarily the man needed to make sure NKVD does its duty. But Beria had a shit ton going against him. First of all, he's Himmler, minus the charm. Second, everyone knows it. Third, he's a Mingrelian. Georgia is not as important now as when Stalin is alive. Stolid Russian names should be on the marquee when discussing the defense of the Motherland and here comes this fellow whom even educated Russians would call a "black-ass," if they should they could get away with it. Beria gets it in the neck. I am not sure how true the rape charges are, but I just want to say this - everyone sure seems to believe them. Though there is one element of the stories that dovetails too neatly into official history: Soviets were prudes. They may have talked of sexual liberation in the salad days of the October Revolution, but they sure looked down upon sex as soon as they won the Civil War. Beria the Rapist gets an easy hate and purging a pervert is easier for everyone to accept, considering the rest of the charges in the OTL '53 purge read like lunacy today (he was accused of being a Japanese spy, IIRC). There is also the fact that when Yagoda (the now thankfully forgotten Chekist leader) was purged, there was a lot made about the fact that foreign pornography and a dildo were found among his possessions when his house was tossed. As I said, the Soviets were prudes.
Now then the folks I have climbing up the pole once the dust settles:
Kaganovich. I weighed this list heavily towards survivors, and how Kaganovich, one of the few out and out Jews who never hid his identity, managed to survive the dog-whistle anti-Semitic horseshit years of Stalin must be counted for him. And then there is also the fact that in '41, when told his brother was showing "rightist" tendencies, Kaganovich said nothing to protest it, but called up his baby brother and then his brother shot himself and Kaganovich said nothing of it later. Kaganovich was also in charge of Heavy Industry and the Bolsheviks had a hard-on for industrial capacity. Kaganovich either gets a bullet in the back of the head or a seat at the table, there is no in-between, and considering Kaganovich was a capable man, I say he gets a seat.
Khrushchev. As I said, I like survivors. And considering how many died and how few lived when Khrushchev was First Secretary of the Moscow Regional Committee... Khrushchev might not have been anyone's idea of a leader at this time, but he outlived stats that are utterly insane to fathom. Then there is the fact that while Zhdanov went to Estonia, it was Khrushchev who went to Poland to supervise the orgy of killing that went on there in '39 on the Soviet side. But the reason I don't see him making the initial table is because Stalin's death in June of '41 would find him stranded in Kiev and supervising the defense of the whole of Ukraine against Nazis. And rushing off to Moscow would then be interpreted as abandoning his post in the time of war. Also, nobody would be in a hurry to get him a seat, unless Kaganovich (his mentor) drags him there. But I think Nikita would simply bide his time and wait for the right moment to strike.
Malenkov. We get a funny vision of Malenkov, the born loser, a pudgy puffball whose big claim to fame was to be on the other side of Nikita in the struggle. But in '41, he was a man on the make. It was he who was in charge of the cadres of the Communist Party of the Soviet Union, effectively making him Stalin's Bormann, minus the personal influence. Malenkov's power, however, would have been noticed and he was not yet a full member of the Politburo. Thus, in the immediate aftermath, he would be left to lie fallow.
Once again, I like survivors, and that is why I think as in OTL, in post-war scramble, Khrushchev gets the nod. He survived Moscow. And I like winners.