I did once a re-enacment at Waterloo in a rather big group (we were about 100 in the unit) with the goal to see what a common soldier saw when marching on the field - and my experience is that practical all my attention went on how to behave with the others in the unit, and to follow the orders. of the unit-commander. And extrapoling my view to the whole or even to a bigger part of the battlefield wasn't possible (if I don't take my knowledge of the battle and of the battlefield into the account, what was the purpose ) . So it's my belief that the memoirs of a soldier or even an officer concerning a particular battle is mostly based on what he learned afterwards and not on his experiences during the battle itself. A batallion commander had a greater view but his main intrest will also be the overview of his own unit, in attack and in defense. Only brigade and higher commanders may have had a broader view of how a particular situation on that particar part of the battlefield where their units were involved .

What concerns the historical value of memoirs , most aren't written following the methodology of historical research and don't take into the account the fact that a memory is in most cases fooled by the mind, as is a basic law in psychology. To write a memoir one should have to return to that actual battlefield within a short time to review his experiences , which wasn't the case.
"people in high-stress environments, especially those involving risk-taking, have a distinct biological response involving the endocrine system, which affects the way their bodies work and how their minds process data to assess risks and determine actions. The most common physiological response is well-known as the ‘fight or flight’ adrenal response in
which the hormone, adrenaline, prepares the body for short-term action. This affects the blood supply to the internal organs, including the brain, causing non-essential activities to close down while, at the same time, causing the survival functions to become enhanced." (neuroscientist John Coates in his 2012 book The Hour Between Dog and Wolf)

For Waterloo, take for instance the case of Ney, or even Soult , who served already in the battle of Mont-Saint-Jean in July 1794, where also the Hougoumont farm played a distinctive role , and who even didn't remember the difficulty to attack that same farm 21 years later, while Wellington, who served at the same battle under the command of The Duke of York, remembered this site quite well 21 years later.

And the best book written about Hougoumont is the one by Alasdair White "Of Hedges, Myths and Memories", free on the internet in the following link http://projecthougoumont.com/wp-content/uploads/2017/02/Of_Hedges_Myths_and_Memories_A_historica.pdf

Marc