I'll type this slowly so even you can understand. We have seen this type of nonsensical casting over and over and over again. And each time we see it, the movie that is eventually released is always subpar. If you cast Jackie Chan as Abraham Lincoln, or Justin Timberlake as Michael Jackson, I would make the same argument.
Hope this helps
IMHO, the best stories have a clear protagonist (which Opp had) a clear antagonist (which Opp didn't have until the end) and a plot (each event is caused by previous events) rather than an episodic structure (a series of things that happened) Opp's biggest failure was the antagonist and the story structure. Failures in casting and/or story structure are why so many movies these days feel less than satisfying after they are viewed.