Medel joined City for around £11m in the summer as the club embarked on a spending spree to try to prevent them from falling foul in a relegation battle this season.
"He's a hard-working player. He's a holding player and aggressive, we know that. He likes contact with other players," said Rangel, according to Wales Online.
"But I do think Cardiff paid too much money for him because he's a holding midfielder not a goalscorer.
"He is a record signing but I think he has done well, along with Steven Caulker who was great for us. Even at a young age he showed he had great potential at the back. I thought he was going to sign for a better team, but he signed for them so fair play."
Rangel's Swansea will renew their rivalry with Cardiff in a few days as the sides meet in the Premier League this weekend.