Yeah, Garrincha was next level..
It's funny, in this clip at 2:20 people say that in modern football that the defenders would never start walking blah blah blah, but in reality that clip was taken in the final minute of the Quarters and the Czech defender is asking Garrincha "Haven't you done enough?"
On what you said about defense is funny, because Brasil's best defense has always been it's Offense. All of our best defenders have been "Attacking Defenders" Cafu, Roberto Carlos, Nilton Santos etc. We never really had a Beckenbauer for example.
Now in regards to Ronaldo v Romario, the play styles like you said are so different. Theres a couple things that makes them different for one Ronaldo was never afraid to score a "ugly" goal, theres tons of clips of him putting it right on top of the keeper taking deflections and going in. Also, it's tough to find a clip of Ronaldo ever heading a ball in to the back of the net, for him it was take it on the chest and hold it with his strength. I do agree with you too..Romario was much more clever, in Brasil when talking about Romario the first thing that comes out of peoples mouths are usually "Cold Blooded" He'd take the ball in to the 18 yard, and start walking around he didn't give a fuck. Also Romario's ability to jump and head balls was amazing, especially for someone of his size. In the end I would say it's a tie, but due to the amount of marketing help Ronaldo received in the eyes of the football world he's greater.