I haven’t yet seen “Valkyrie,” but I’m pretty familiar with the relevant history, and will be interested to see how accurately it is reflected in the film.
It appears that–as is the case with almost all writing/video dealing with the German military conspiracy against Hitler–the film is strongly focused on the activities of Colonel Count Stauffenberg. It’s easy to see why filmmakers would want to emphasize Stauffenberg’s role and story–with his aristocratic lineage, his good looks, his attractive wife, and his love of poetry (he was a devotee of Stefan George), the man makes a fine dramatic hero. Stauffenberg was a complex individual and a man of many quirks, some of them likeable–like his habit of lying on the rug with his wife and reading English novels together, each waiting for the other to finish the page–and some not so likeable, like his tendency to lose his temper if his boots weren’t lined up precisely by his adjutant. One can see why he would be attractive to writers and movie-makers.
However.
There were quite a few German officers involved in the plot against Hitler, and some of them committed themselves much earlier than Stauffenberg did. Hans Oster, in particular, could reasonably be considered as the driving force behind the whole enterprise. It’s interesting to note that no one playing the Oster role shows up in the cast list for “Valkyrie”–there may be legitimate dramatic reasons for this, but I hope that the movie at least gives credit in some form to Oster’s very important role.