Is ter Stegen a good choice?

Okay so hear me out. If ter Stegen is to leave Barcelona, it is to get more playing time. We have Joe Hart, and if he doesn't start, I don't see him staying. So basically if we get ter Stegen, it is to replace Hart, who I don't think needs replacing. Competition is good, but you cannot have 2 goalkeepers starting every other game. It fucks up our already fucked up defense. Thoughts?