Hmmm. That's not the impression I got reading the adventure and so not really the impression the players got.
1. Everything I have read, including, I think, a quote by James Jacobs, states that the first encounter is supposed to be pretty easy with little risk.
2. The initial encounter with goblins shows them more comedic and not really very dangerous.
3. The opening blurb for part 2 emphasizes how everybody is laughing about the "silly goblin attack."
4. Part 2 is supposed to take place over several days, until a really high GMPC ranger randomly shows up and states that goblins are becoming more organized. The PCs are then placed in charge of the town, while Shalelu goes to investigate, and Hemlock goes to
I got the impression that the initial raid is just 2 or 3 tribes, while the actual planned assault will be all of the tribes.
These series of events, really confused my players. They start the adventure, the first session is some fun games and festival interrupted by a goblin attack. Then they are told, "good jobs, thanks for being heroes. No more adventure here." And told to just chill in Sandpoint for days. Every time I've played/ran it, the Players want to be running off looking for clues immediately, especially after the tomb is opened. I remember when I played, it was extremely frustrating because, as a player, you are ready to start the adventure, and there is just kind of a lull. As a gm, both times the players really did not want to stay in Sandpoint for the days until Shalelu showed up, they wanted to go do something.
So my thoughts are
Part 2 will have the NPCs from part one lauding the PCs as heroes. If they wish to immediately go search out goblins, I will let them. They can make some knowledge/survival checks and point to different parts of the map. I have some mini-adventures from the comics, community created resources, and Wayfinder that can help flesh out the region. They may run into Thistletop early, or they may encounter other goblins, or they may encounter nothing.
Aldern will still invite them on a hunt. At times when the PCs are present in Sandpoint, I will run the encounter with Ameiko's father. The encounter with the skeletons in the tomb will be a little more happenstance, either the PCs overhear the gravedigger talking to the sheriff, or he comes straight to them.
At this point, of the PCs press Sheriff Hemlock or the Mayor, things will be downplayed. When Shalelu shows up, she will state that she tried to make it back before the festival, but got delayed. She will hear of the raid and assume that was the assault she had heard hints of. At this point, the sheriff will have pressing business in Magnimar and mentions that he will also ask for some more assistance. Shalelu says she will make sure nothing else is going on. Everything is still thought to be fine and the players are left cooling their heels.
Part 3 triggers. The players "discover" Bethana worried over the note, but she doesn't know what to do while the sheriff is gone. The PCs volunteer to help. After going through the glassworks..
The sheriff is still gone and now the corporal is over his head. He "lets" the PCs deal with it because he has no better idea. He would rather wait for the sheriff or Shalelu, but the PCs obviously won't let him.
This might help the players stay invested and make relationships with a few townsfolk.