Attacking or harming someone you do not have a direct conflict with begs for retaliation. Merle kidnapped Glenn & Maggie, which was a domino effect leading to the destruction of Woodbury. .If Merle parted ways with them, with no hostility, Woodbury might be functioning today. Or, if the Governor--after Maggie & Glenn were rescued--called it even (knowing it was all about the two kidnapped strangers), Woodbury still stands.
What Rick's group is attempting with Negan is worse--its a seek and destroy mission at a point when we can assume Negan knows nothing about ASZ. At best, the Saviors who chased Daryl, Sasha & Abraham know there were people in the general area, but after all of this time in the ZA, had no clue about the whereabouts of the ASZ. For all they knew, the trio were wandering scavengers--no one local. In fact, the unit Daryl killed did not know. That means it was possible for Negan to never come across the heroes at any time in the future, but thanks to Rick essentially waiting to shoot him in the face after ringing the doorbell, he's asking for a group:
- now known for beating people to death (remember the line in the last episode)
- a group who said they usually introduce themselves by killing one of their captives.
Keep in mind that you might think that is the "direct conflict" I said they did not have, but dead witnesses means no intelligence, no location, no direct conflict. Rick's group is begging for what is going to happen. They would have been better off letting Hilltop handle its own problems.