In my opinion, the German spawns in the last sector are too close to the flags, especially considering that the 1st and 2nd sectors are already quite difficult, and that the Americans have a long walk from their spawnpoints to the last sector as well.
At Crossroads, the German spawns are about 20-100m, or 5-15 seconds, away from the Flag zone, and the closest area of the flag zone is decently defensible (it's behind the wall the flag itself rests on). At Orchard, the spawns are all very close to the flag, including one in a two-room-two-story building in front of the flag, and one IN the flag zone.
The Orchard spawn in the flag zone is especially egregious, as it's on the 2nd floor of the nearby two-story building It's the building type with four square rooms on the 2nd floor, and to make things worse, the door from the staircase to the spawnpoint is blocked with a door (only case I've seen of a door in one of those buildings, I think). This is an incredibly defensible spawnpoint, as the windows face the German side of the flag, making tossing a grenade in difficult for the US). Plus, as you're clearing this building, you aren't even in the flag zone until the very end anyways, adding to the trouble.
So my suggestion is thus: move the German spawns in the 3rd sector back, some distance from the flags. (If they want to spawn closer, the Germans have squad leaders too...) There's even a nice train station back there that I think few players have seen, so possibly spawn them there?