No it's not impossible, there will be a Helmsman in the new Type II Interiour:
http://www.subsim.com/radioroom//sho...d.php?t=176001
The newer submarines like Type VII and IX were actually steered with the mentioned buttons when rudders were moved with electric motors. When the auxiliary motors did not work or energy had to be saved, the rudders were moved with the wheels around the buttons.
Best regards, MCHALO.