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.
By that logic, kill them all. But Negan's end game here isn't revenge, it's control. He wants Rick's group to be highly functioning, but subservient. He wants them to become his hunters and gatherers, so that on his monthly visits he gets half of their supplies. To do that, it helps to have a leader who is smart and capable, but broken.
Ultimately I don't think Negan gives a crap about his people who died. He will replace them with Rick's group and carry on. What he can't have is anyone challenging his authority, and right now he thinks he has Rick under his thumb.