When I was researching my book, "Wellington's First Battle", it became apparent that Mackenzie took command of the 3rd Brigade on the 10th October 1794, leaving Wesley in command on the 15th September. Sherbrooke's account certainly exaggerated the numbers of the French cavalry, so may also have exaggerated his own role.

Unfortunately the letter that Wellington wrote to his brother soon after the action doesn't seem to have survived, instead we are left with a subsequent letter written on the 19th referring to the thanks of the Duke of York.

Regards

Garry Wills