Seriously, if you led a couple of hundred men and a dozen or so got killed, how p!ssed would you be?
I would have killed Daryl, Abraham and Rick. These are the most dangerous, through size, reputation or leadership position.
I would have left Maggie and Glenn (as they have a kid they would be easy to intimidate). Probably leave Aaron and Eugene as they looked suitably intimidated.
It's likely Sasha and Rosita would probably go the way that attractive women do in these situations. Michonne would probably have just been killed for trying to defend herself.
So, yeah Glenn, Carl, Eugene, Aaron, Maggie, Rosita and Sasha left. Put Glenn in charge on the understanding Maggie and thier kid would be in danger and most of the muscle and leadership dead with the rest traumatised.
Yeah, I had similar thoughts. I was struck by the sharp difference between realistic behavior and the narrative necessity of the story. Realistically, Negan would kill the warriors and keep the weaker members as slaves. There is no logic in keeping a 200 pound cop who just declared his intent to kill you alive, and kill the 160 pound regular guy with a baby on the way.
However, the Walking Dead is Rick's story, always has been. All the other characters exist to give him something to love, mourn, and avenge. I noticed how they kept cutting to Rick's face as Glenn was being killed. It wasn't Glenn's story, it was the story of Rick being broken.