I clicked the link but only got to Facebook. I am not a member so I can't see any painted figures. Can you post some?
In the Osprey MAA The German Army in World War I (3) one of the color pictures show a Finnish NCO of the Prussian 27th Light Infantry wearing the steel helmet and puttees. An exact copy of the AIP German infantry.
This unit was formed of Finns who came to Germany from Czarist Finland and joined the army as Jagers. This unit returned to Finland in 1918 and fought in the Finnish Civil War on the White side. They also were the basis of the officer and NCOs of the Finnish Army.
A good wargame could be put together for later war Eastern Front battles.
I was even thinking of a fantasy wargame with German troops in the Carpathian Mountains, pine trees, Cossacks, Bolshevik sailors, and vampire castles!