One thing that never gets discussed in polygamous relationships is just how good the male lead will have to be to make it "work", either through believability or through suspension of belief or pure autism. Most anime romance leads are dunces, and even when they are good (e.g.- Hikigaya, Ichikawa, Foutarou) I can't see them being with more than one chick. The only ones I can believe will make a poly relationship work are Emiya Shirou and Rentarou, and again one of them is autistic enough to turn his wives gay for his other wives.