“Though he was a dedicated soldier, he detested Naziism.”
Apparently not enough to not fight for them.
Like some other great military men he made the wrong decision on whom to fight for over misplaced or mistaken loyalties.
Generals sometimes are in the unenviable position of choosing the lives of their soldiers over the desires of the politics. We often say, “If he really believes that, then he should resign.” Well, if he resigns who does he leave his soldiers to...a butcher, an incompetent, a sadist?
So, staying with your troops is sometimes to protect them from something worse.
It’s never been possible for a person to look at their current situation through the lens of hindsight.
He was informed what most suspected (his friend later confirmed) and was dumbfounded.
He also suffered tremendous PTSD from WWI: that's why he was such a meticulous planner-- he knew the stress of anticipating battle would make him violently ill for a few days just before an attack, so he carefully planned and rehearsed everything with his staff beforehand. As soon as the battle started, the sickness dissipated.