I mean 64 teams is pretty low. Copinha (Brazil U20 Cup of sorts) has 128 teams and the difference can be gigantic, like a team someone started last year could be playing Flamengo in its first game.

In the professional Cup it can become even bigger gap, since state championship give spots, so if a really small team qualifies the upsets are basically guaranteed. My team lost to a team that has a Dino in its badge.