Page 14 of Nafziger's "Napoleon at Dresden The Battles of August 1813" which is part of the Chapter "The Armies Refit 8 June – 10 August 1813" says:
The allied armies were in desperate shape. Most of the Russian infantry regiments consisted of a single half strength battalion. The Russian cavalry and artillery had taken similar losses and their horses desperately needed to recover from their year of campaigning. The Prussian infantry and cavalry regiments were filled with reservists and new levies. These levies had an average of less than 3 months under arms. They had one strength, they were fighting in their homeland for the survival of that homeland.
Page 17 – says "… after the battle of Bautzen, the regiments serving in Germany generally consisted of a single battalion and had strengths ranging from 150 to 200 men.
Nafziger footnotes suggest Friederich "Geschichte des Herbstfeldzuges 1813" as the supporting text.
Best bet for a usable order of battle and approximate strengths appears to be carl von Plotho "Der Krieg in Deutschland in den Jahren 1813 und 1814" as he has the OoB for 1 May. I am afraid the text is in German fraktur and unfortunately not all of the text is clear. Volumes downloadable link
Text in appendices suggest strength of each Cossack regiment about 250 – 500 men, artillery battery 150 men, jager battalion 400 men, line infantry battalion 300 men, cavalry regiment 300 to 500 men.
gets started with Flintloque.