Spain and Brazil are the best..so if we have a comparison between them then.. if u go by overall the only problem Spain has is LB (unless u play any of the CB/RB in the LB) otherwise its amazing team with RB (Ramos) CB (The Barca duo) and in the midfield is where Spain wins by far... Xavi, Ineista, Fab, Xabi, Silva omgg so many options... in the attack Villa, Mata, Torres (or u have other options too)
with Brazil.. u have LB (Marcelo) CB (Lucio & Silva) RB (Maicon or Dani).. in the midfield u have Kaka, Lucas, Ganso (and offcourse u can convert some postions, like i see many people use Robinho as CAM).. in attack u have Pato, Neymar, Hulk..
so its a good comparison between Spain and Brazil.. only if Spain had any left back 82+ i wold have been amazing ...