Negan has to hit back in a huge way, so yeah, just a single killing would be nothing. We've seen what, at least 30 Saviors killed so far vs. one death from Alexandria? At this point, the only single death that would shock their world would be Rick and we all know that isn't happening. They're probably banking on the huge fan support for Daryl, but that won't be enough.
All I know is that I'm glad Abe has been given a reprieve. This world needs more Abraham-isms.