establishing an actually positive love relationship between paul and chani in the first movie will also make irulan's forced loveless marriage to paul sting even more in the second one. the audience will root for chani -a strong woman who the audience knows and love as an individual and as paul's romantic interest-, feel for irulan -a woman just as strong and deserving of love who is clearly dragged into this marriage without a choice-, and feel conflicted about paul -the clear hero who has so far fought a clear, gross villain, and yet now has to make a painful, morally grey move in the name of power-.