The 172/182 engines have a diiferent timing set up , and the timing belt does not run the water pump.
The 197 / 200 does use the same timing belt kits , but they run the water pump, so this acts as one of the idlers for the timing belt.
The 197/200 do not suffer from as common failure as the 172/182 , but i have seen it (3) and heard of it.
Its never normally the actual belt that fails , usally the tensioner / idler / water pump bearing , and my advice to anyone would be to have the belt kit and waterpump changed at the recommended interval ,using genuine parts for correct fitment and the warranty , and i am not sure as to why they have the interval , but will try to find out.