I have dug out my notes taken from `Das Preussische Heer der Befreiungskriege` Volume I, published in Berlin in 1812, republished in 1912.
In the cavalry section is a diagram of a squadron in line, with 4 troops (Zuege). The standard is in the centre of the line; ahead of the standard is the squadron commander; in the front centre of each troop is an officer; behind each troop are 3 NCOs; to the right of the front line are 3 trumpeters.
12 paces behind the rear rank of the troops, in the centre, are `partly-trained recruits`.
So, the Prussian cavalry (at least by 1812) seem to have had the normal, `continental` cavalry squadron deployment.
Alex confirms that Russian cavalry deployed in two lines and this can be confirmed by the Borodino panorama and by diagrams in `Sabli Ostry, Koni Bistri.. ` by Alla Begunova, page 121.