On Tommen: Tommen is a pawn who is King. Who has his ear will have the power. Cersei was able to drive Margaery away and humiliated Tommen. She has her control over him. On Joffrey, Taking into account the season 3 scene of Joffrey referring to Renly's Perversion it is surprising no thinks Joffrey will be revealing in Margery torment.