Not to belittle your point, but calling Marx a socialist and Engles a capitalist is a kin as calling Jesus a Christian who’s disciples were Jews.
Cowbee didn’t do that. Cowbee said that Engles was a Capitalist, i.e. he had Capital, I am reading it as if you are mistaking it for Liberal? Cowbee also didn’t call Marx a socialist.
Neither of these links show OBJECTION accepting a genocide.