I personally like simpler setups for newbies (to forum mafia), but if he's willing to play a more complicated setup, I say let him.
In other news, speaking of face-to-face mafia, I was running a few games of it (six players) recently. We were doing night starts to make it get to an odd numbers of players during the day. Most of them hadn't played before, so I just did a simple setup with one mafia, one doctor, and one cop (I don't think doc-cop is as broken in smaller setups, especially when most people haven't played).
So, one game, the mafia (one of the people who has played before) killed the other person who has played (he was a VT), and upon day start he instantly claims doctor. Another Vanilla Townie (yes, it's true) claimed doc as well, saying the other was the mafia. After a bit of arguing, the VT said he just claimed doc because I had said before the game that it's a bad idea. The real doc claimed, but everybody agreed that the VT was the scummiest and they lynched him. (During the day, the cop claimed as well for no apparent reason.) That night the mafia and the doc both targeted the cop. The cop targeted the mafia. The mafia said he protected the cop, but then the cop said that the mafia was the mafia. The mafia said that the cop must be scum. I caught his logic flaw instantly, but nobody else did for a while. After probably 10 minutes of discussion, finally the doctor realized it all and they instantly caught the mafia.