Are all cultures morally equivalent?

I would suggest that it's difficult to first define a cultural equivalence of any kind and then to find universally agreed upon moral standards across all aspects of that culture. What is inevitable is that all cultures are built upon success and failures. Where you get to in the end can be somewhat undercut by what you did to get there.

I think it's better to focus on individuals in the vast majority of cases. It's far more of a level playing field.