I 100% agree with this, but it has to make sense in the plot, otherwise it turns me off as it doesn't make sense... In his game I can only SE Alice willing to share the MC with Leah and if we stretch a bit with Melody... Currently she hates the Aunt, so no go there, and Katrina is like everyone's pet, they think she is adorable and cute, but want her to go to her pen when the family is doing something important...
A game I can see a harem ending for if the sister/childhood friend learns to chill the fuck out is Offcuts, as the girls don't live together or really hang out, so the MC can bang all without the others knowing except the ones that do want in on the orgies.