It probably means nothing, but when I was applying for grad school, there was a requirement to submit a previous work, and basically the only piece of writing I had at the time that I didn’t feel revolted by was a nearly-exhaustive critique Popper’s lecture Science: Conjectures and Refutations as pertains to Marxism. I think there were a few points that I forgot to address, but really the only difficulties I had were finding ways of deconstructing his sophistic, ironically anti-science rhetoric and also following his knot of self-reference to other works so that I could actually work with a complete argument that didn’t use “well, I proved this point in a book I wrote” as axioms. Looking back on it now, I don’t think it was a great essay, but it was fine.

Anyway, I gave this essay to very anticommunist academics and they thought I did a good job, so I was accepted. I agree with you that the vast majority of academics don’t have any substantial familiarity with Marxism, sometimes really none at all, and yet many still feel that they can speak authoritatively on it and don’t hesitate to do so. I nonetheless believe, and this was my purpose in writing this comment, that for most of these people you can present good arguments to them and they will accept them as being good arguments. You aren’t going to change their mind on almost anything, but they will simultaneously not just thwart you for being a communist (depending on the person). I guess that’s what happens when someone really believes in liberal pluralism.

I also encountered people who understood that liberalism stands against democracy and therefore explicitly adopted the position of opposing democracy. They ultimately were so tied up in spewing fatuous nonsense that I just couldn’t deal with them because I lacked whatever elements of personal character would be required to deal with someone who almost never speaks in good faith.

Anyway, I think it’s unlikely that you’ll find some kind of model Marxist mentor, but I believe that especially for writing a PhD, you should be more oriented toward educating yourself with constructive feedback given from your advisors on a conversational basis rather than seeking an ideal mentor. It sucks that they don’t have the knowledge we would hope for to direct you to pertinent information you didn’t already know about Marxism, but just having people who can follow and critique arguments on a deductive basis and have knowledge about adjacent topics (you can’t defend Marxism without attacking liberal paradigms, which they usually will be familiar with and strenuously defend) should be enough.