There is no difference between Scolari and Dunga. Scolari preferred had a mediocre team with Fred et others he wanted; he never knows to play in 4-3-3 because this team has no # 9 or try Hulk for more activities. David Luis is not bad, but he can't play in central defense, because he has no discipline. Luis may play strongly in the middle avec Ramires. Miranda and Luis Philipe ATM, Magenqhos and Lucas PSG are the good solution for Scolari.
Dunga preferred a mediocre team with Wagner Love then call Ronaldinho who was very good. Remember Scolari has great team for Confederation Cup, he may have little bit credit because he said, he worried about the fitness of this team, as Paulinho, Oscar, Hulk and Fred never show their physical condition to help the team with Super Neymar.