This is all accurate and important stuff. However, I'd caution against leaning too heavily on the liberal/Left or liberal/Marxist distinction. There are plenty of lib-bashing MLs who just so happen to fall in line with the leftlib consensus but get there by other means.
Any dyad like that is vulnerable to capture by cynical elements - "What kind of Marxist doesn't support open borders? Aren't you just a liberal?" Becomes a map vs territory problem where magic words can exempt you from scrutiny, then we're back to square one.
