If you can be more specific, I can take a crack at explaining, but I can’t really go off of what you’ve provided other than the transformation “problem,” which I can address in short and link what I believe to be a more in-depth explanation of common criticisms of Marx’s Law of Value.

Essentially, Marx’s hypothesis that there existed a formula that he was never able to find that could solve for the difference between Capital Intensity and the notion of profit equalization across industries ended up being wrong, in that such a formula did not exist. However, we can see with empirical evidence that Marx’s Law of Value ends up being correct, in that profitability is closely tied to Capital Intensity, and that equalization of profit across industries really just does not come into play outside of noise.

This wasn’t because Marx was stupid or anything, but because math itself had not advanced enough to show that such a transformation did not exist, but this does not disprove Marx’s Law of Value, rather, it affirms its more important foundations while dismissing a hypothesis of Marx’s that he never fully developed, nor could he have.

Here’s a link to the article.

As for the Vanguard, you should read about the Mass Line and Democratic Centralism, both address your issues.