that doesn't invalidate the statement. theoretical analysis of oppression is often necessarily simplifying because, as you pointed out, life is infinitely complicated, and sometimes you have to gloss over potential complicating factors if you want a political statement more specific than "oppressed people are oppressed by their oppressors". and once you've identified a generalized pattern of oppression, say, men oppressing women, you can begin to interrogate how that is impacted (intersected even) by other patterns of oppression