Concerning the saxon mutiny (see link), you are right, mutiners did not shoot at prussian officers, they only threw them stones. And even suppressed by firing squad in saxon guard batalions, the mutiny started again in two other batalions.

Saxons national aspiration in 1813 make them willing to fight Napoleon. But annexion of half their country, and forced transfer to prussian army, despite their oath to Saxony King, was much more than what they could accept; and Blücher had to deprive himself of 14,000 men at the beginning of the campaign, keeping only two regiments of cavalry.

Also, if Prussia annexed "only" 40% of Saxony, it was largely due to opposition of Great-Britain, Austria and royalist France against Prussia and Russia. A side effect was that, at odd with one another, all these nations except France still had large armies ready to fight when Napoleon came back.