You write, "I am still surprised at the level of trust you place in his recollections. "
C.'s discussion of the situation with the horses during the campaign seems to be insightful. C. was N.'s personal "horse" man and I think that it can be trusted that he understood the care needed to keep horses in the field. So, when C. describes how even early on that the calvary horses were unshod and the reason for is that the necessary forges for the blacksmiths were lost in the back of the train. Do I trust C. in this? Yes, absolutely.
C.'s recollections of conversations with N. Who knows? They are certainly interesting and vividly describe the personal character of N. during this campaign. For example, C. wrote numerous times about how N. would, in various contexts, make reference to being the victor of Austerlitz. Can C. be trusted here? Yes, I think he can.
On the other side, Lowenstern's memoirs are at times hard to trust. I think he made out Figner to be a scapegoat for the execution of French soldiers in the field. In his memoirs he writes that after the Battle of Bautzen his commanding officer told him that he was to act as a partisan unit behind enemy lines. Then, the actual locations were the executions took place are very remote little out-of-the-way villages. I'm pretty convinced that Lowenstern knew more than he's letting on about this. What was Figner supposed to do with 200 French soldiers? It was a critical retreat after a lost battle, they were unattached cavalry units, ordered to act as partisans, with no field support, in the middle of nowhere. It was a situation with little or no difference from Jaffa.