I can't recommend Wawro's book on the 1866 War. He produces a number of howlers in just the first five pages of the book. I can't trust his accounts of the battles. For instance, throughout the book, he consistently talks about the Austrians attacking in "Half-battalions" when they were still using Division Masses where battalions formed THREE two company 'masses'.
I have yet to read a contemporary account where the Austrians formed 'half-battalions.' He draws a straight line between the French columns used at Valmy [sic] to the Austrians' decision to use column shock tactics when there isn't any such straight line.
There are a number of other real problems with his analysis, and I would be glad to explain. Take the whole thing with a large grain of kosher salt.
Get it from the 'horse's mouth':
Prussian Captain May's criticisms of the Prussian Army in the 1866 war A Tactical Retrospect
and von Molkte's replay written by Colonel Bronsart von Schellendorf:
A Reply to the Prussian Campaign of 1866, A Tactical Retrospect.
Major Albrecht von Boguslawski,Tactical Deductions from the War of 1870-1871
Capt. E.H. Wickham, Influence of Firearms on Tactics 1876
Robert Home Precise of Modern Tactics 1882
And those are just some of the studies on the topic during the 19th Century.