I took a bit deeper look at the Finnish Army. Most of their infantry units were referred to as Jäger battalions.

More than likely, a Finnish Infantry Division (Jäger) consisted of three or four Regiments from various regions of the country. Each regiment would consist of three battalions. There may have been a brigade of Artillery with whatever systems that were available; maybe 2 - 4 battalions in the Division Artillery Brigade. Their supply and maintenance systems could have been piece-mealed from both military organizations and civilian volunteers close to the front. I'm watching the movie now. I see plenty of civilians bringing food and supplies to the front lines. 

I read about the Sausage war last night. The Russians infiltrated behind the Finnish lines when they found a gap created by casualties. The officers thought this was wonderful and pushed their men through the gap. When the Russian foot soldiers smelled the sausages cooking in the field kitchen, their individual desire to eat; because they were starving took over. The Finnish soldiers took advantage of this and picked off all the Russians who went for the kitchens. They massacred them simply because they were desperate to eat a meal.