On the other hand, in some eras there was even greater fluidity, because in the middle ages especially, most of Europe consisted of land controlled by various nobles with often only nominal suzerainty of a king, and every time one of these landed nobles died or inherited or married the borders would change, and there existed hundreds of semi-independent states in modern Germany alone. That can't be represented well on a map this scale.
Secondly, the thing you're observing in Italy is just the normal functioning of the Roman republic, which elected two consuls every year.
Thirdly, the "single malignant character", aka the "Great Man Theory" of history, is honestly very simplified and not really accepted by modern historians. A modern historian would rather say the societal conditions were ripe for a warmongering dictator to arise, and would point to many factors outside the existence of any one individual as instrumental in creating that set of circumstances.
Overall, your observations show just how intellectually dangerous it is to draw broad conclusions from such a simplified presentation. It's neat to see, but it's far too arbitrary and simplistic to draw any sweeping conclusions about history from.