I think Terzic would be the most usual candidate. He knows the Bundesliga well and is a coach who managed to take Dortmund to the UCL final last year. I think Bayern hastily made an early decision. Although Kompany was one of the best defenders in the world during his football career, it is obvious that his coaching career did not progress in the same way. I hope the Bayern management will not regret this decision.
To be honest, I doubt that Kompany can make Munich better next season. Yes, in my opinion Terzic is much better because as you said Terzic knows the Bundesliga very well. I don't know why the club management didn't choose to negotiate with him but there is a possibility that they have also received a rejection from Terzic or they are not aware of the fact that Terzic has left Dortmund. In my personal opinion Kompany still doesn't have the level to coach a team of Munich's level. I'm not underestimating Kompany but statistically Kompany doesn't have a good enough background. But I hope Kompany can prove the trust that has been given to him by the club management.