How does one make a point using an example they know nothing about? To be clear, I agree with you, but as someone who has read a fair amount of M&E and know a ton of people who have read M&E, they are among the top 1% of readers in terms of sheer volume, but also curiosity and intellectual honesty.
Combined with the fact that the vast majority of Marx and Engels was social science, not ideological polemic, I get the impression that you are giving advice that you haven’t actually taken. Which would be fine, we are all contradictory beings to some extent. But it does beg the question.
And if you had read them, then I would want to know your insights on what you had read