One interesting concept could be how the endoskeleton technology might be integrated into the ninja world. For example, it could enhance a ninja's physical abilities, like giving them super strength or speed during combat. It might also change the way ninjas train, as they would need to adapt to this new technology.
It can fit in by adding a new layer of technology. The endoskeleton could be a secret project in one of the hidden villages, like Konoha. Scientists or ninja engineers might be working on it to give their village an edge in the ongoing power struggles.
Julius Caesar's story is based on actual history. While some details might have been embellished or simplified for storytelling purposes, the main events and his existence are factual.