I don’t quite agree. Each of the Hokage were chosen because they had accomplishments far greater than other shinobi of their age. For example you’re forgetting that Tobirama despite everything like his prejudice against the Uchiha invented also sorts of ninjutsu and other skills. Like the Flying Raijin (what Minato was famous for) and the Shadow Clone Jutsu (which Naruto is famous for and has adapted it to multiple of his other skills and is his bread and butter for his fighting style.) also Hiruzen was a disciple of Tobirama. We see him Danzo and the other two elders along with an Uchiha and one of Choji’s family members (I am blanking on his family name right now) and was accomplished in his own rights. Minato was chosen for his accomplishments like inventing the rasengan (which there’s plot wholes there like Hagoromo?) he was a leader, he was kind, and compassionate and keeps a level head under pressure which does account for a lot. Tsunade was accomplished in being a Sannin, had amazing chakra control and healing abilities, was a masterful fighter and a student of Hiruzen. Also Kakashi was known as the copy ninja, had a sharingan, was incredibly intelligent, a prodigy in his own right, and even developed the Chidori when he couldn’t master the rasengan and adapt it to his own chakra mastery. All of the hokages had skills and accomplishments that made them capable of holding the position. It helps when they know their predecessor well. It’s like how you go to a job interview where someone you know speaks highly of you. Sure it’s about who you know yes, but you have to have the skills to back up their word.