Louis XXIV
Le Roi Soleil
I trust Sid, because I have an idea of his background. Unfortunately, Sid isn't involved really.
I don't know about Shafer. I have to say I do not trust him.
I trust him somewhat because I've interacted with him in the past. I know Soren Johnson would be involved in chats here or at Apolyton on occasion, but always as a representative of Firaxis. Jon Shafer was a poster. I remember him being an OK Civ3 player and I have no idea about Civ4 as a player. But I do remember that he was really involved with modding. I know the guy knows history. I'm trying to remember which scenarios he did with the Civ4 expansions, but I think I remember that they tried to do a little bit different using some extra coding.
Honestly, my biggest concern with him would be that he's been too involved with Civ. A lot of times, fans of the series feel that it's perfect, it just needs added complexity. Thankfully, the early previews seem to indicate that he's not doing this. He seems to continue Soren's philosophy of Add 1/3, remove 1/3, and keep 1/3 the same (not sure the math actually works there, but I believe that's how he presented it).