Um... maybe it is you that should do the reading.
Finland was allied with Germany until 1944. Hence the fact that there are 109's with Finnish livery in the game. It wasn't until the Finns threw the Germans out in 1944 that they started fighting them. Therefore, Finland fought on both the Axis and the Allied side in WW2.
I'm not an expert on the subject, however I don't think Finland was ever allied with Germany, merely co-belligerents, along with; Bulgaria, China, Croatia, Denmark, Hungary, Manchukuo, Romania, Slovakia and Spain.