It´s not even close by any measure: No one won as many races on as many different courses as Merckx. If you want to blast him for doping, blast him for getting caught, because back then there were very few pro cyclists who were not doping.
Lance is the greatest Tour de France cyclist and perhaps the greatest return from a sickbed in history, but that´s about it. He is only in Merckx´s catagory when in relation to the Tour.