It was strange to see how Elias lasted all of the 90 minutes in that match. He was okay with keeping possession and being a shuttler, but defensively, he was very loose. He was too easily pulled around as well as Fred in Brazil's midfield. Fernandinho did a good job positioning himself and closing down the danger areas, but his tendency to close down the ball holder aggressively will be a problem as he doesn't have the protection of Luis Gustavo. Brazil's ultra-aggressive game was okay against Peru's lack of attacking quality, but it'll be suicidal for them against better attacking sides.
I feel somewhat bad for Dunga. With Gustavo out injured, he doesn't really have a proper defensive midfielder to rely on. With what he started off with in midfield, it made it tough for Brazil to attack as all of their attacking threat was only from out wide. Things did improve once Fred went off, but there was still no proper attacking midfielder who could dictate play from the middle. At the moment, they're too reliant on Neymar for good work from the middle.
Peru did well to assert themselves in the tournament. They defended with numbers at the back, but once they had the ball, they moved it around quite well with a quick tempo and good rhythm. Of course, since it was Brazil, they couldn't commit too many men forward, so they struggled to deal with Brazil's high-pressing setup with a few players forward, though Guerrero did a great job as a target man.
This Copa America looks quite competitive at the moment. There's no team that looks like running away with it, and every match has been close to even as well.