I think that the current beginning of a fortress is a bit... bland. You have no idea where your fortress' wagon and people start from, you have no idea how you got your resources, or any of that stuff. So, I'd like to give this idea; the idea of a Prelude/Beginning to the fortress crew's setout.
First, you choose the typical resources/dwarves and location of the fortress, like normal. Then you choose the fortress, mountainhome, hamlet or other such structure that your wagon will start from. After this, you start in that starting location, with a new message;
"Your proposition for a new outpost - [Fortress_Name] - has been approved. [Mountainhome] has granted you the supplies you need for your expedition, so long as you can make the trip there. Before you are to leave, however, you and your six allies must prepare your belongings. The wagon leaves in three days; time is of the essence."
The player then is in charge of the Expedition Leader on the outskirts of town, where the Wagon is situated. The wagon, at this moment, will be completely empty. Some of the dwarves may be nearby, but not all of them. This is because they are preparing for the journey, collecting their belongings, and saying goodbye to their loved ones.
The player then has three days to either talk to their fellow dwarves, or gather extra supplies for the journey to the mountainhome. Once the three days pass, the dwarves will all be collected together at the wagon; with more possessions.
Each dwarf will have brought some personal items and placed them within the wagon. These items depend on the dwarf and their main job; For example, A hunter may bring a quiver, extra arrows, or a crossbow. A bard may bring an instrument.
Then, you have to travel. You and your party will have to travel to the mountainhomes, or the nearest fortress connected to the mountainhomes, and move to the trade depot. From there, your materials will be supplied, and you have to load it all up to your wagon. You can choose to stay for a few days, or get a move on to your fortress' site. Once you start moving, you must protect your dwarves from animals, feed them, and give them drinks. You'll need to prepare - not just for the fortress itself - but for the journey to it. As you travel, you can pick up even more resources, but the wagon will keep going unless you stop the animals. You can also fast travel with the wagon, but this makes you miss out on extra resources.
When you finally arrive at your site, the wagon stops, the screen fades to black, and the default 'Strike the Earth!' message appears. You are then able to do what you'd like in normal fortress mode.
How is this idea?