Abu,
good question. The Sopwith has a slight adverse yaw which needs to be countered with rudder, but more importantly, without rudder you get a skidding turn in which the nose never comes around to track the turn --- it is always pointed a bit to the out side. In a full scale plane the pilot would be pushed to the out side of the turn a well. You can fly with out coordinating, but it looks --well--uncoordinated (-:

If this doesn't help, I'll try again.
Walt