Roman Legionaries Vs. Medieval Heavy infantry

[Domen]

the lack of logistical supply in the medieval era

Another myth (with maybe some exceptions, mostly from the Early Medieval).

But even examples from the Early Medieval prove something different.

When Duke of Normandy William (later known as the Conqueror) invaded Britain in 1066, his fleet had ca. 1000 ships. By comparison when Julius Caesar invaded Britain in 54 BC, his fleet had ca. 800 ships.

So much for the "lack of logistical supply"...

Also William the Conqueror gathered his fleet and his large army from his tiny Duchy of Normandy.

By comparison Caesar gathered his fleet and his army using resources from a much larger area.

Compared to the Parthians, medieval kingdoms (...) were poorly equipped on the infantry level.

Rather inversely - the Ancient Parthians made no use at all of heavy infantry.