Yes. For example, in 'The Once and Future King' by T.H. White, Arthur is a central character and this work has elements of science fiction as it often re - imagines the Arthurian legend in different ways that can be seen as having science - fiction - like qualities.
Since I don't know the specific 'Arthur Lee Love Story', it's hard to say who the main character is exactly. But if it's named after Arthur Lee, chances are he is the main character.
I'm more inclined to believe it's a fictional creation. Think about it. The stories are so full of romanticized ideas like the noble knights and their quests. It seems like a story created to inspire and teach certain values rather than being based on a single, real individual. Although, it's possible that some real events inspired parts of the story, but overall it's a work of fiction.
Arthur himself is very notable. He's the central figure, a king with a mysterious origin who pulls the sword from the stone. His leadership and the legend that surrounds him are what make the whole story possible.
The main characters of the following novels were King Arthur:
"Public Execution Begins from the Stupid Hair King": The main character, Su Yun, appears in the form of the Stupid Hair King.
The main character, Molos, is a defective sword spirit of the Sword of Pledge and Victory, and is related to King Arthur.
"Douluo: Getting King Arthur at the Beginning": The protagonist Yun Tianhe got King Arthur's martial soul at the beginning. I hope you like my recommendation. Muah ~