How can it be possible, seeing a Lybian archer with 190 range while a Egyptian, the most advanced Civilization in Bronze Age, have its archers with 150 or 160 of range? Medjay archers? Kushite archers? The bow does not give a increased range because of its shooter but because of the quality of the bow. Impossible.

They should have more reload but not better bows that allow the user to have increased range.

Not sure what you are talking about. 

Renowned Upper Egyptian Archers are 190 range, so are Elite Medjay, and the Kushite Armoured Archers are 200 range while the Nubian Mercenary archers at 230 range as are Nubian Longbowmen, and the Renowned Nubian Longbowmen so 230 range is the longest umodded range for archers in Dynasties. 

Range is determined by a combination of unit tier and unit regionalization by faction and native rosters.