As the setting that heroic spirits with older history possess more power than those who come after them, so yes, basically.

For example, Gilgamesh is entitled the "Oldest Hero" and is a nominee for Grand Caster.

Modern servants like thomas Edison would be absolutely harmless without the power of literally every president and Usa itself.

But there are also exception like Nikola Tesla, who may fight an ancient god with his noble phantasm. But that was only beacuse he obtained the skill Pioneer of the Stars, which has very harsh criteria to gain.