because there's a lot more too it than just basic radiator area. the core efficiency, thickness, pressure drop, air flow, coolant flow rate, thermal efficiency of the engine etc, etc.

the suzuki would have been designed for the asian market where temperature and humidity are much different to europe and cooling systems need to cope. doesn't really change things these days are vehicles are designed for a global market generally, but they weren't back when that ford was designed.

not forgetting that the suzuki has an oil cooler as well