I do too. Hopefully the option will come up down the line.
I also think you should have been able to save everyone in the Brotherhood (except maybe Astrid and Arnbjorn. I actually thought of a good way of doing it too. For every special condition of the contracts you fulfill )the ones that earn you a "bonus"), the person who gave you the job will be alive with half their health when you reach the Sanctuary. If you're fast enough, you can heal them.
The only ones not affected by this are Veezara (who would be covered under Bound Until Death) and Arnbjorn (who I think is better off dying to be with Astrid anyway).
Thoughts?
Personally, I find the DB quest line super linear. Why can't we investigate Astrid herself? Maybe instead of saving them through contracts, how about undercovering secrets of Astrid's and sharing them amongst the DB members you can trust. The ones who have gained your trust. Thus the will be aware of what to come next. I think the only person you wouldn't be able to convince is her husband no matter under any circumstance. "I like you, but I don't like youthat much, my wife wouldn't do something like that"
Like after you save Cicero, there should be a new quest line where Cicero gives you evidence against Astrid herself or something. Or Cicero comes up to you and tells you what he has uncovered. Even Lucian Lachance ghost states at some point that Cicero is the wrong person to look at. So, why aren't there more options to branch through the story?
Like when Astrid tells you to do this mindless random quest instead of going to the Volluun grave you should be able to either obey the Night Mother or obey Astrid's words.