Immediately Darryl and Carol assume the hospital group are adversaries. Once they get Carol, Daryl knows he has to get reinforcements for battle.
I know they've encountered *******s before but they seem to assume they will have to fight every other group they face. Noah hasn't told them what they're like inside, just that they have guns and people.
Was there any thought about negotiating, like hey you have our people, we want them back?
No, the previews suggest they want to ambush them, assume that they will have to take the hospital group out. They don't know about the mega bitch running the hospital, the sex slavery, etc.
They're going to prepare to kill dozen or more people to get Beth and now Carol back.
They could for instance say, if you don't give our people back, we'll systematically hunt your people down, so every time they leave the hospital, we'll whittle their group down, which would affect their survivability.
Or better yet, capture these cops whenever they leave and do a prisoner exchange.
But no, they're going to take all of them out at once, even if it means a big confrontation often results in casualties, including death.