I could see that if it was a more complex, namey name getting reused in different positions. But it's just a very simple one-syllable sound. Right here on Earth, we can have Lee Lee, Lee Leigh, Leigh Lee, Leigh Leigh, Leigh Li, and Lee Li all using the alias Le Chiffre. Not to mention all the more complicated sounds that have their place as both first and last names -- Martin Martin, Jackson Jackson, George George, James James, Gerald Gerald, Fitzroy Fitzroy, Landon Landon, Alexander Alexander. I'm all for stronger creative naming (too many of the new names are too dire, and I'm still waiting for EU writers to recognize that three-letter full names are not a hundredth as common a thing as they all seem to think), but I don't think Marr is really in the problem area here.