No comrade, Lamarck predicted epigenetics! /s

In reality they were all wrong to a significant degree and also usually contributed significantly to some aspect of what is taken for granted as the 'correct' scientific knowledge

For example, it's been known Mendel must have faked his data for almost a hundred years, but that doesn't make Mendelism wrong (after you strip out the stuff that is wrong)

Not exactly, the only thing that he was correct about in that regard was the existence of a material carrier of heritable information. Literally everything else he conjectured about it was wrong like thinking that it would be continuous rather than discrete and so on.

Very briefly, you'll often see references to

• Vavilov being pushed out because of Lysenko
• Lysenko being responsible for the 1930-33 famine, despite not being responsible for leading agricultural research like Vavilov actually was at the time
• Stalin supporting the ideological aspects of Lysenkoism, even though there is a draft copy of the speech that Stalin cut to bits (including something mocking like "haha, and what is the class character of Darwinism??")
• zero reference to all the racist eugenists whose work was underpinned by genetics of the day
• Lysenkoism being described as pseudoscientific even though, from what I have read it is not a radical interpretation of some of the experimental findings
• aspects of it are quite correct (like young crops responding better to winter by exposing them to colder environments - which increased expression of a few genes that influence cold adaptions)

Don't get me started on the claims about the Lysenko influence on China's great famine

You read something simple that says China banned the use of chemical fertiliser following Lysenkoism, then read an article from 1958 that suggests China was pretty keen on fertiliser