Allowing miners to use the same pick for fighting and mining, woodcutters to use the same axe for fighting and woodcutting and hunters to use the same crossbow for fighting and hunting.
More importantly...
Plagues! The main killer in the real mediaeval times. Too much miasma in the fort will not only make unhappy thoughts, but also spread diseases (like forgotten beast syndromes now) among the dwarves, causing !!fun!!. Dwarves with low butchering skill may produce bad meat, causing other illness. Migrants and caravans can import them too, as can animals. Babies and children would be especially vulnerable, potentially leading to tantrum spirals if the bereaved parents are not consoled.
Also, I know this will never happen except in mods for some strange reason, but, as another feature linked to plagues, sewage. Too much of it inside causes miasma and disease. And, of course, if Urist UselessNoble issues 1 mandate too many, she could always be treated to a one way trip to the cesspool. It would also make for some wonderful artefacts.
"This is a mudstone bed. All craftsdwarfship is of the highest quality. It menaces with spikes of magnetite, pear wood and mule bone.
On the item is an image of a dwarf. The dwarf is retching. This refers to the killing of the dwarf Urist Daggerdagger by pestilence in the year 251 in Boatmurdered.
On the item is an image of a dwarf and sewage. The dwarf is drowning in the sewage. This refers to the drowning of the dwarf Urist Uselessnoble in raw sewage in 252 in Boatmurdered. Armok have mercy on her soul!"
And the worst thing about all that is that noble dwarves would actually love to sleep on a stone bed covered in spikes and images of rancid death.