Minato is probably a remnant of the Senju clan, and very probably related to Tobirama.That's why Hiruzen raised Minato, it's because he was the best student of Tobirama, exactly like what Shikamaru is doing for the son of his dead master, Hiruzen is raising the descendance of his master.
Smart like Tobirama, fast like Tobirama, tactical like Tobirama, a sensor like Tobirama, he touches the floor to sense the ennemies like Tobirama, he has the same fighting style as Tobirama, the same poses, he is the only one to use Tobirama's signature jutsu and he was raised by Tobirama's best student.
Think about it, how did Minato became such an invincible beast if he comes from a fodder clan?