It always bugged me that "T-47s" got retconned into meaning the Speeders. Why the hell would a medical droid worry about Speeders? In the original movie, the line is clearly meant to refer to some kind of MEDICAL devices:
2-1B: Sir, it will take quite a while to evacuate the T-47s.
Luke: Forget the heavy equipment..."
So we're supposed to assume that 2-1B is now evacuating snowspeeders? It's idiotic.