In real-life trolley problems even the committed utilitarians (like commanders during war time) are likely to hesitate before sacrificing lives to save more.
This, at least, seems to me to be entirely appropriate for a utilitarian. If you don’t hesitate before sacrificing lives, you’re likely to miss opportunities to accomplish the same goal without sacrificing lives.
If you have one option which is clearly superior to your known alternatives, but that option still leads to outcomes you would seriously want to avoid, then you should probably make full use of whatever time you have to look for other possible options which would be superior.
This, at least, seems to me to be entirely appropriate for a utilitarian. If you don’t hesitate before sacrificing lives, you’re likely to miss opportunities to accomplish the same goal without sacrificing lives.
If you have one option which is clearly superior to your known alternatives, but that option still leads to outcomes you would seriously want to avoid, then you should probably make full use of whatever time you have to look for other possible options which would be superior.