Does this mean "if you defeat a commander, you can become a commander"?
Yes or "win against". The English of the contributors isn't that great at times.
Will update. But there's an on-going debate about how to properly translate "thắng" in all contexts so the team have not fixed these kinds of sentences (that contain "thắng" yet)
I just checked. This sentence has been deleted and Incubator cannot locate the sentence anymore. It is not supposed to show up here. Please let me know if you encounter it again.