Hooooooooo boyyyy.
My brothers and I actually talked about this sort of idea before. The end result was that the yanderes who placed the MC's wellbeing and happiness above their own desires got smart and realized that they should work together.
In this way, they would become the MC's personal army of go-getters, each one using their own unique talents and skills to somehow better and enrich the MC's life. Also, when working as a group, it made it a lot easier to keep the unworthy ones away - those being the ones who wanted the MC selfishly to themselves without caring about his happiness.