Why did the Roman's conquer more land than the Greeks?
The Romans used the Mediterranean Sea as their superhighway. Alexander the Great's conquered territory had slightly less landmass. But land transport is 30 times more expensive than water transport. You have to feed camels and donkeys. Thus by 142 BC the Macedonians were kicked out of Seleucia by the Parthians. The Romans also used the Thames, Seine, Rhine, Danube, Rhone, Po, Ebro and Nile rivers.