There's a lot of changes and additions I would make. The existing advisors are really underwhelming and unimaginative, unsurprising because all the current Soviet content is a holdover from the game's initial release.
There are a lot of advisor traits that don't make sense, either.
Vyacheslav Molotov has the "Smooth-Talking Charmer" but anyone who knows anything about Molotov in real life is that he was more or less the exact opposite of this. Most people who know a bit of history about WW2 will primarily know Molotov as the Foreign Minister, but in reality he was more like a general Plenipotentiary, Stalin's right hand man. He was also head of government until 1941. In my opinion, a unique trait, or silent workhouse would be really appropriate for Molotov. Regarding alternate history stuff, Molotov was a hardline Stalinist and should be probably arrested and executed if either Trotsky or Bukharin come to power. He could potentially be a purge victim as well. Historically, his wife was arrested and throne in a gulag, seemingly as a warning by Stalin.
I would probably make Kalinin a bit more interesting as well, give him a unique trait like "Figurehead Vozhd of the Peasants" or something like that. A stability increase, and an increase to construction speed and infrastructure speed could be appropriate for his huge popularity among the peasants. He should be a potential purge victim as well. He wasn't seen as completely reliable by Stalin due to his friendliness with the Right Opposition in the past. In terms of alternate history, he should probably be purged by Trotsky, but remains available if Bukharin comes to power.
Khrushchev should probably be changed too, to actually be more appealing. Perhaps a unique advisor trait, "Political Commissar" which in addition to the communist drift provides a small bonus to division recovery rate, and attack and defense on core territory. Potential purge victim, but he should probably be left available if either Trotsky or Bukharin come to power. Khrushchev was pretty unimportant in 1936, and he had associated with the Left Opposition in the past.
As far as additions, here are some historical and alt history potential options to.
Lazar Kaganovich. "Iron Lazar", one of Stalin's right hand men, along with Molotov. Appropriate trait could involve a boost to production efficiency cap and resource efficiency gain, while having a sizeable stability hit. He was strongly involved with agricultural collectivization, and he was also Jewish. This made him none too popular among the Soviet public. Hardline Stalinist, should probably be purged if either Trotsky or Bukharin come to power.
Alexandra Kollontai. I would give her an existing advisor trait that we have only seen one time up to now. "Red Sufragette" which provides -10% stability and 2% recruitable population. Historically Kollontai was associated with the syndicalist "Workers Opposition" of the early 20's led by Alexander Shliapnikov as well as her advocacy of focusing on women's equality and liberation. Surprisingly, she was *not* executed in the Purges and languished in obscurity for many years as a diplomatic attache in various countries abroad, and as the ambassador to Sweden during the time frame of the game. She should probably not be available to a historical Stalinist USSR unless the new focus tree allows you to pick the Soviet Union's cultural policies between conservative traditionalism(historical) and a more radical course. Otherwise, she should be available to Trotskyist and Bukharinite Soviet Union.
Patriarch Sergius. Patriarch of the Russian Orthodox Church. Historically, Stalin rolled back his persecution of the Orthodox Church during the war to enlist the support of the Church in assisting with the war effort. Bonuses to stability, and attack and defense on core territory could be appropriate. Should only be available to a Stalinist Soviet Union.
Genrikh Yagoda. Prince of Terror. He should be in the player's cabinet at the game start. In my opinion he should be in as an alternate history hook. He was a sympathizer of Bukharin and I think he could be potentially involved in an anti-Stalin coup that sees Bukharin returning to power. Otherwise in a historical game, he should be automatically removed upon taking the Great Purge focus. He should also be purged if Trotsky comes to power.
Nikolai Yezhov. Prince of Terror. In a historical or semi-historical game, he should be automatically added when Yagoda is removed upon taking the Great Purge focus. He should also be purged by Trotsky. In a hypothetical alternate Stalinist path where Stalin is murdered during the great purge by his own clique, he could stay on as NKVD head, but otherwise he should be removed and replaced by Beria... speaking of which.
Lavrentiy Beria. Prince of Terror. In a purely historical game, he should become the final head of the NKVD after the end of the purges. Should be purged by Trotsky or Bukharin in the alt history stuff.
And of the above.. I honestly would create a new advisor trait, "Secret Police Chief" and retain -30% Foreign Subversive activities effiency and -25% damage to garrisons, but I would remove the extra non-core manpower and instead replace it with an increase to resistance target in foreign occupied core states. This would actually be much more useful to a Soviet player especially because in a historical game or MP game you'll be spending most of your game on the offensive without occupied non-core states. A small boost to counter-intelligence could be good too.
Georgi Dimitrov. President of the Comintern. This should be a pretty good trait, +1 operative slots, small increase to political power gain, and possibly a small war support increase. Historically, Stalin dissolved the Comintern in 1943 as a sign of good faith to the Allies. This should be represented some way in the new Soviet content, with the option between following the historical line leading to the dissolving of the Comintern, or doubling down and sticking with it. Dimitrov should only be available if one does the latter. There should also be an additional check that causes him to become unavailable if Bulgaria is communist, since it should be assumed he will be abroad and a part of their government. Hardline Stalinist. Should be unavailable to Trotsky and Bukharin.
Grigory Zinoviev. President of the Comintern. Same trait as Dimitrov. Zinoviev headed the Comintern between 1919 and 1926. He was expelled from the party for joining with Trotsky to form the United Kamenev(alongside his long time friend and ally, Lev Kamenev). He should be executed in the Great purge, but otherwise be available for Trotskyist USSR, and perhaps a Right Opposition USSR if Bukharin reconciles with Trotsky and invites the left opposition to a subordinate role in government.
Lev Kamanev. Bolshevik Grandee. Stability increase and political power gain. In Soviet politics he is always spoken of alongside Zinoviev. Two peas in a pod. Joined the United Opposition with Zinoviev and Trotsky in the late 1920's and was expelled from the party. Executed in the Great Purge. He should be available to Trotskyist USSR, and potentially, Bukharin if he reconciled with the left opposition.
Filipp Goloshchekin. Red Kingslayer. Small stability reduction and a decent war support increase. Small bonus to division attack could be good too. Goloshchekin is mostly famous for having personally overseen the execution of the Romanovs, but he also infamously played a significant role in the collectivization of Kazakhstan. He was a hardline Stalinist, but was arrested along with Yezhov after he had fallen out of favor. Could be an option for an alt-history stalinist route where Stalin is done away with but the Stalinist clique remains in power.
Maxim Gorky. Famous Novelist considered the founder of the Soviet "Socialist Realism" style of literature. This is more of a cheeky option. He died of illness in the summer of 1936, but stories persisted that he was killed on the orders of Stalin, such a testimony was made during the Moscow Trials. Gorky had fallen out of favor with Stalin in 1934 and had been living under house arrest. He should be unavailable to Stalinist USSR, but perhaps Trotskyist and Bukharinite Soviets.
Sergo Ordzhonikidze. Superindustrializer. I'd give something like a 3% reduction to consumer goods, a 5% bonus to construction speed, and a 5% bonus to resource gain efficiency. At the game start, Ordzhonokidze is probably the second or third most powerful man in the country and Stalin's potential successor(making him a good choice for an alt-history Stalinist route IMO). Stalin became paranoid of him and he allegedly committed suicide during the Great Purges in 1937 sensing his impending fate, but there were also rumors he was murdered on Stalin's orders. Stalinist, he should be executed in the purges in a historical game, and also purged by Bukharin or Trotsky if either take power.
Yevgeni Preobrazhensky. Superindustrializer. Same as the above. Known as one of the foremost, if not *the* foremost Soviet economist in the 1920's, he was a hardline, essentially unrepentant supporter of Trotsky and was executed in the Great Purge. Naturally he should be available to a Trotskyist Soviet Union, but potentially Bukharin if he reconciles with the left opposition.
Ivar Smilga. Political Commissar. Basically the same trait as Khrushchev's. He was initially aligned with Stalin in 1919 during the the latter's campaign at Tsaritsyn, but by the end of the year he had become a staunch ally of Trotsky. A member of the Party's Central Committee in 1917, he was later expelled by Stalin and executed in the Great Purge. He should be available to Trotskyist Soviet Union. He could also double as a potential general, as well.
Alexei Rykov. Silent Workhorse. A close associate of Bukharin and proponent of continuing the 'state capitalist' NEP. A member of the Central Committee in 1917, he was also later expelled from the party by Stalin for being a pillar of the Right Opposition along with Bukharin and Tomsky. He should be executed in the Great Purge, and also purged by Trotsky if he takes power.
Mikhail Tomsky. Trade Union Boss. Could see production efficiency cap and factory output increase. A close partner of Bukharin during the period of the Right Opposition. Expelled from the Party and executed by Stalin during the Great Purge, he should also be purged if Trotsky takes power.
For High Command options, I don't really have any ideas here. Political, economic, and social history is my thing. The military side of things in its specificities is pretty unimportant to my area of study so I admit to being fairly ignorant of it.
However, it seems like Trotsky should be an obvious Army Chief option if Bukharin reconciles the left opposition, or if Trotsky has returned to power and then later retires. This would also be an interesting opportunity to allow other potential leader options, like Ivar Smilga, Nikita Khrushchev(if you're feeling particularly cheeky since he was associated with the left opposition in the past, having him as a potential Trotsky successor seems like a good meme), or even Trotsky's son, Lev Sedov(murdered by NKVD agents abroad in 1938 historically).
Paradox actually make a pretty good new advisor portrait of Trotsky in Man the Guns for Mexico that could also double as a good general/field marshal portrait.
Anyway, just spitballing. I think advisors should feel powerful. Small boosts to stability or war support are often something that's not good in the long term since it's not difficult to reach 100% war support without any special advisors at all. You can eventually reach max stability by improving worker conditions too, so I feel like advisors should offer something t hat feels pretty beneficial even in the long term.
Obviously this should be counter-balanced with a more difficult starting situation. The Soviet Union in particular should have a messy political and economic situation starting off, much more difficult than it has now.
If the Soviet Union doesn't have many advisor options and the ones they have aren't good, it's definitely not for lack of suitable material to work with.
