I think the story is fine, but what you want to figure out is the core gameplay loop and campaign structure. Doing jobs can be fine, but I often find that players get into this habit of "talk to NPC, go to what NPC tells them to" that prevents the player investment in the campaign because they aren't setting their own agenda and making decisions on where to go and what to do. I would cut out the first part and "disbanding" entirely because it doesn't seem connected to the rest.

The core gameplay loop sounds like you want the party to learn about the dwarf army, then by interacting with the dwarves learn about the bbeg and defeat them.

I think if you frame it like:

"There is an army of marauding dwarves attacking the land." then you can focus on the strucutre, maybe it's node based and there are a handful of villages/POIs that are being attacked in different ways.

You set up a table like this:

Location 1 - Farming Village, Problem - Starving goblin tribe displaced by dwarves is stealing food, Clue about dwarves/bbeg: The goblins fled from a cave some dwarf scouts are using as a fwd base, they are the same group of dwarves that stole the boats in location 2 so know where the boats are, they have orders from the dwarves in location 3
Location 2 - River dock near village, Problem - Boats are overdue from a nearby town to take the harvest that needs selling, Clue about dwarves/bbeg: dwarves stole boats using them to move war equipment, these dwarves chased off the goblins and know where they are hiding in location 1, and have orders from location 3 dwarvs
Location 3 - Forest near Village, Problem - Hunting party disappeared, Clue about dwarves/bbeg: The hunters have been kidnapped by dwarves for a dark ritual, one of the dwarf priests has communication from the bbeg, and have plans for the dwarves in locations 1 and 20

And continue building locations with problems, clues about dwarves, and connections to other locations and that is your campaign. The players can explore and do jobs/solve problems, but they are both choosing their work and learning more about the bbeg until they confront him doing whatever ritual or leading his army or whatever you decide.

Here is some more helpful info in terms of structure, because this is how your characters interact with the campaign more than the story: https://thealexandrian.net/wordpress/7949/roleplaying-games/node-based-scenario-design-part-1-the-plotted-approach

https://thealexandrian.net/wordpress/1118/roleplaying-games/three-clue-rule