You do realize that the World Health Organization tried to rank health systems once, in 2000. The findings were justifiably critiqued in relation to method and data availability & quality. Even experts in measurement and favourable to such an attempt were forced to conclude it was a failed exercise. 

As such, the WHO has not attempted to rank health systems since that one attempt more than a decade and half ago. But amazingly, people still like to quote 2000 report like it has validity or value.