You can’t ignore that he was Jesus Christ and replace him with a commoner because him being who he was is why they chose that method of internment. It doesn’t matter if he actually existed, or if the story is fictional. All that matters is that the choices were made based on the situation, whether a fairytale or fact.

Jesus was a spiritual leader and Messiah for one group, an agitator for another group, and a dissident and rebel for a third group. He was far from a commoner, and had thousands of followers in a time when that was a monumental feat.

A commoner wouldn’t be entombed like Jesus was. Jesus’ followers didn’t want the body desecrated. The Romans and Pharisees were concerned that his followers might steal his body and claim that he was resurrected. So the choice was made to intern him in a cave, and seal the door with an enormous boulder. That’s why this method was chosen. Ordinarily such a burial would be reserved for someone wealthy, since the manpower and resources required to do so was considerable.