IMO Mohammad is a religious character created for a political story. He's possibly based on a single person, certainly the possibliy exists, but is more likely mostly the fanciful imagining of ancient theologians, doing what they do best - make up religous stories.
One could ask: Was there a real Achilleus and what does it mean "real Achilleus"? Perhaps there was a great warrior that fought against the Trojans. More likely there were various brave warriors who fought various wars. Surely the mythical Achilleus in Homer's Iliad is 99% myth mixed with the deeds of what we expect a great warrior to have done. Homer was a story teller and he told a story to people who wanted to hear this sort of story. At that time Greeks were in LOVE with the Hero Archetype.
So, was there a real Mohammad? Again what does it mean "real Mohammad"? Perhaps there was an Arab person who fought against other Arab tribesmen. That is possible. Or, there may have been many such men. But surely the mythical Mohammad in the Qur'an is 99% myth mixed with the deeds of what Arabsexpected a great Prophet of God to be. That Mohammad, is political-religous myth. A story written by story tellers, vetted by politicians, and sold to an audience that expected such a person to exist.