Here's the dynamics. A tail dragger is unstable. The CG wants to lead the drag so a tail dragger always wants to swap ends.
Huh? With a tricycle or tail dragger the CG is always between the wheels. Otherwise the model would tip up or down at rest.
Ground loops are caused by engine/prop torque and differences in lift of the wings (i.e. from a cross wind - upwind wing has more lift). Tailwheels have no correlation to ground looping. You just don't see nose gear on designs noted to ground looping, short coupled airframes like WWI biplanes, because there is no where to attach one.