Yes, its clear now, and as you understood my message was not specialy in response of yours .
About casualties you're probably right for some, but look, after a battle, one of the first thing a colonel cared about, was probably casualties into his own regiment, the same for a brigader etc .. even if wounded himself . And infos had to be brought from one division to an other . And as many memorialist said, they had notes .
So, to me it sounds not so strange if such colonel or general has had good datas . Relating the truth is an other question .
I was talking about Marbot's . Do you remember the pages concerning the effectives always over evaluated not to hungry Napoléon, and his proprer "astuces" to know something closer from the real numbers .
Even if some are lying, numbers wre known .
This exemple was for before one battle (Auterlitz).