Those guys are hiding behind the wall next to the mill.
I loved the sniper level, you have to move really slowly through it. It's like your hunting the Wehrmacht. Once you get to know generally where the sniper positions are and where they generally hide it's a blast.
As for the snow forest level, I have to admit im not a huge fan but if you move slowly enough you can spot the enemy before they see you. You do have to move very slowly and quietly and just keep on scanning every few steps. When you spot a flak gun, try to find the positions of all the guards before opening fire on them and watch out for the snipers on the tops of the hills. It can take you a while but ive gotten through that level with only 5 hits.
------------------
It's our wits that make us men