Ok, at this point you've lost me.
I don't see how any of this is relevant to the point; that Marxist agricultural policies disincentivized production and thereby created shortages. Even your point about mechanization (which I have answered) doesn't really fit; a tractor certainly allows you to produce more food for less effort, it does not mean you use the tractor to its full potential. You still haven't in any way addressed the point; that a farmer in the Soviet bloc and chums tended to have little motivation to actually work to his full potential.
In regards to the Tsarist economy, you are exaggerating my claims in the opposite direction. I said the economy was not medieval, which it wasn't, not that it was a prosperous system in which all had a merry time. Conversely, you also exaggerate the achievements of the USSR. In actual fact the Soviet economy struggled to do all these things. There were frequent shortages and queues, and in some cases, simultaneous over-stocking with warehouses full of goods that could not be sold because noone wanted them; they were junk. The important point here is not the direct comparison of the two, rather it is that the Tsarist economy was going somewhere, and if things had continued as they did one would likely have seen a Russia better off than it is today, whilst the USSR's achievements are exaggerated and indeed, were almost certainly not the best course for the Russian economy.
Your point is completely bonkers, my fancy mathematics was meant to solve for the missing part of your point, well not yours: many share it with you. I agree that collectivization did disincentivize production, the USSR agreed with that point as did China. Both abandonded the early collectivization efforts for a multitude of approaches, again many of which have counterparts in the west. What my fancy mathematics does is to solve for the missing part of your (collective) argument which is to answer why the shortfalls of the Soviet and Chinese agricultural economy persisted.
The problem with your argument, aside from being counterfactual is that it simply does not make any economic sense once you take development into account. In a non-mechanized situation where a peasant works half the time on the state farm and half the time on his own it does hold up. When the peasant becomes a labourer and drives a tractor on the state farm we can entertain the idea that he can make some money on the side but his work on the mechanized state farm is magnitudes more productive than his side business. The black market effect of state set prices makes an incentive for the labourer to moonlight as a farmer but it fails to account for why the USSR agriculture was unable to make the USSR self sufficient or efficient.
The USSR solved its agricultural inability with imports, as did and does the UK and with few exceptions Australia among them: so does the rest of the world. Not being self sufficient is not a failure on it's own unless you have Juche aspirations. It is unlikely that the USSR even with a developed field of Agronomy would have avoided the issues that arose in Transoxania. It is likewise also unlikely that the USSR would have within its time had much direct gain from a well developed field of Agronomy. Ultimately the USSR succeeded in feeding in its population, clothing them, motorizing, educating and so forth.
The Tsarist economy had nothing at the time, the Bolsjevik economy had something at the time.