Everything would be scripted and played out, thus not a freedom style
simulation of a fantasy world where near anything can happen, we love dwarf fortress because it allows us to do said freedom and because of said freedom we can set our own goals for nearly everything.
Unless the goal/scenario takes place in a different world, it would seem to fit more to the adventurer.
And this is starting to sound like some achievement for a valve game... one in dwarf fortress would be more badass because of said freedom that allows us freewill to do nearly everything within the said freedom.
Example:
Wolf in Sheeps clothing (some name like that) achievement
Kill 700 goats (or some herdable animal, sorry i stole your example)
If this was to be an achievement than the player would continue to play the game with the feeling some sick twisted sense of a good job.
Where as if it was a goal/scenario... the game would most likely end there
Although to edit some parts of the game to say... increase the rate at which something happeneds,what herd of animal or thing shows up next at your fortress and the rate they come... (zombie madness anyone?), would be more fun than the average undead groundhogs I get.
[NOTE TO SELF: undead sonic the hedgehog is a must to mod in... will show results when I mod it in unless its already been done.]