Pelé's era was different. European football wasn't the be all, and end all of club football in those days. The Campeonato Brasileiro was much stronger 50 years ago, than it is now. Before the trend of almost every big South American talent leaving the continent began (late 80s-early 90s), the Brazilian domestic leagues had the likes of Zizinho, Guia, Ademir, Djalma, Nilton, Falcão, Jairzinho, Carlos Alberto, Garrincha, Jorginho, Gérson, Vava, Bellini, Júnior, Zagallo, Zico, Tostão, Socrates, Rivellino, Sócrates playing in Brazil at a level that was close to to, or coincided with their peak; apart from foreign stars.
And Pelé did test himself against the best Europe had to offer. eg. Benfica was probably the strongest team in Europe when he met Santos (or Top 3 at worst) - with players like Simões, Germano, Augusto, Coluna, and a certain 20 year old named Eusébio, who was scoring at the rate of a goal per game. Pelé's Santos tonked them 8-4 over 2 legs (including a 2-5 rout in Lisbon where Pelé scored 3 against the European champions):
Limited sample size, but others vs European teams:
Real Madrid when they had Di Stéfano:
Inter Milan at the height of Catenaccio
2 goals vs Barcelona when they had Czibor and Kocsis
vs Stade de Reims
IIRC, something like 35%+ of Santos' goal vs European teams were scored by Pelé. So he was tested by European clubs.