Yeah, but your reasoning for that conclusion is flawed. Killmonger caught a rough lot and he found away to rise above it, but his way involved charting a course through live that involved him killing a bunch of people. And then when he did get power, the first thing he did was establish that he'd rule with an iron hand, make moves to prevent any chance of anyone being able to follow him as king, and try to kick-off an international revolution built on violence. His capabilities for leadership pretty much begin and end with his ability to inflict violence on those around him. How does that make him a better leader than a person that is willing to take action when needed and also reflect on what needs to be done and alter his stance based on the information available? T'challa was the better leader. All Killmonger brought to the table was some insight that was missing in Wakanda, and T'challa, like a good leader would do, took that insight to hear and made decisions based on it.