I wouldn't change it. Bravo for La Liga is an awesome option, he is less sensational than Stegen, but also less prone to errors and in a league competition that is an amazing quality. Plus, he knows the players from the league and he has experience. Also he is a leader, being the captain of Chile in front of players like Vidal and Sanchez is a testamant to his strong character and also to his personality. Ter Stegen will play plenty of games, considering Champions League, Copa del Rey, Club World Cup and Supercup (both domestic and european). It's like 12 from CL, around 10 for Copa, 2 from the Supercup, 2 from the Club World Cup, 1 from Europe Supercup. That's about 25 games. Not bad, considering that he plays in the Champions League, against the best players in the world.
I think Bravo made 1 error in the entire league campaign. The goal he took from Banega. Amazing.