Linearly combining utility functions does not force you to reward utility monsters. It just forces you to either be willing to sacrifice large amounts of others’ utility for extremely large amounts of utility monster utility, or be unwilling to sacrifice small amounts of others’ utility for somewhat large amounts of utility monster utility in the same ratio. The normalization scheme could require the range of all normalized utility functions to fit within certain bounds.
Linearly combining utility functions does not force you to reward utility monsters. It just forces you to either be willing to sacrifice large amounts of others’ utility for extremely large amounts of utility monster utility, or be unwilling to sacrifice small amounts of others’ utility for somewhat large amounts of utility monster utility in the same ratio. The normalization scheme could require the range of all normalized utility functions to fit within certain bounds.