My Tarkin-related storytelling complaint is that Tarkin + Vader + Krennic is (at least) one main villain too many. It is narrative bloat for the sake of fan service. (Spider-man 3-esque) This might just be a taste thing but I prefer a more efficient sort of storytelling than that.
No, you are absolutely correct BMH. Krennic should have been the only villain in R1, plus Vader in the very last scene.
There was absolutely no need to have Tarkin in R1, not even the Death Star, which should have just been alluded to and remained an ominous threat off-screen.
But bad storytellers are gonna bad storytell. And the fans gotta have that fanservice and all.