Forgive me if this has been brought up already, I've searched the forums and haven't seen it mentioned. Infantry in winter uniform don't show up in Thermal view. Red or Blue in several scenarios. They are visible in Daylight scopes and external view.
"Commands" from the Tank commander to the driver are far less formal and vary widely from one crew to another in the US Army, at least way back when. Let's go! Move out! Left....left....your other left, dammnit! slow down! you get the idea...