I've gone for Pic - no particular track record, Junior in the team, no significant development experience to contribute, no prospects to speak of in that car, no particular money, no particular friends in high places, and the team will need a scapegoat, probably quite soon.
I assess Pic as the least secure, although Massa's on notice to perform this season or he's out as soon as he climbs out of the car in parc ferme at Interlagos.