That kind of confidence is pervasive in every aspect of their being. They don't have room for doubt.
Reading about wartime generals solidified the thought in me. Many generals like Patton weren't even very gifted strategically, but they were confident and authoritative in their decisions. Oftentimes, that's enough to pull off a victory.
Edison and Tesla were definitely NOT equally capable. Tesla was an absolutely genius inventor and scientist, and Edison was a genius businessperson and good inventor. (Or something like that, TBH it wasn't Edison's biographies I poured over in highschool!)
Tesla received life-long backing and support from Westinghouse, major investment from JP Morgan, and more.
Edison tried, and for a chunk of time, did succeed at pushing Tesla out of the way, but I'd strongly argue that the things that sunk Tesla were not ways that Edison pushed him out of the way, nor would I argue that Edison ever really succeeded at pushing him out of the way.
Is that what you mean?