Pass completion rate not up to scratch?
For one, it's arguable that he wasn't even the best player on the team. Many older Brazilians, and especially at the time, thought Garrincha was the better player. Secondly, he was always in an incredibly talented team. In fact, in 62 he missed out on the rest of the tournament after being injured in the first game and Brazil, led by Garrincha, still went on to win it. In 1970, he was arguably in the greatest team of all time, still cited today as a standard. Aside from all that, he played football in much more tactically naive environment - teams still used variations of the pyramid formation with 2 defenders at the back. In fact, the 58 tourney didn't allow subs based on tactics to occur, only for injury IIRC. Whilst he has a fantastic goal-scoring record, it is incredibly inflated by his record in Santos. He scored, on average, 3 goals a game whereas at the same time he never once topped the goal scoring charts in the world cup. He never played in Europe and went to the US after his days in Santos.
Compare that with Maradona who practically single-handedly led Argentina and Napoli to titles. 86 will always stand out as the standard for any player with claims of all-time greatness. What he did with Napoli against Sacchi's Milan, with all that talent, is quite unbelievable - classic David vs Goliath. Furthermore, the game was far more tactically aware - Sacchi pretty much changed football tactics with his time in Milan - and just as rough. People talk about Messi, but I'd like to see him do half of what he does when defenders are routinely trying to end his career with tackles that may not even garner cautions.
That's why I think Pele is overrated. I reckon amongst most footballing fans he isn't rated as highly and it's more his fame transcending the sport that has kept his name in the mix. Fifa needed a star and Pele was willing. He is amongst the best, sure, but I would put Maradona ahead of him fairly comfortably. You could transport Maradona from his era to now and he wouldn't look lost at all IMO. Pele would probably be still wondering if he is still playing the same sport - a joke, but you get the idea.