There is a fine line sometimes between the right proportions and visa-versa for what makes a plane groove........assuming that there aren't any mechanical reasons for a loose rudder.

For yaw stability, the side view of the whole plane needs to be considered. Crude execution of design, like 3/8" slab tail surfaces with blunt edges and crooked fuselages that need rudder trim to correct can't help much. Same goes with hinge gaps

I think the case of the plane with a big nose / too little tail is what creates most of the swimming tendencies that can't be trimmed out or corrected with slop free linkage.