The Cessna 172 and Piper Warrior are similar in many ways, including their engines: for most of their production history (1968-1998 for the 172; the entire history for the Warrior) both were equipped with a Lycoming O-320 engine of 150 or 160 horsepower.
One significant difference between the two is in their before-landing checklists: the 172 instructs the pilot to turn carburetor heat on before closing the throttle (p. 4-19):
Carburetor heat should be applied prior to any significant reduction or closing of the throttle.
Conversely, the Warrior recommends carburetor heat "if required", and even recommends against it unless necessary (p. 4-23):
Carburetor heat should not be applied unless there is an indication of carburetor icing, since the use of carburetor heat causes a reduction in power which may be critical in case of a go-around. Full throttle operation with carburetor heat on can cause detonation.
Considering that these two aircraft have very similar engines, what would explain such a drastically different approach to the potential danger of carburetor icing?