I find it ridiculous that if, for example, I want my Legendary Armoursmith to make a steel spear, he's as useful as Urist McSoapmaker.
I'm proposing that certain skills are associated with each other, such as the smithing skills, food preparation skills, melee combat skills etc, so that having a large amount of experience in one specific skill will render the dwarf not completely incompetent in a closely related skill.
I think this should be something along the lines of gaining exp in related skills up to a certain level, say Adept, at a significantly decreased rate to the skill actually being practiced. For example, Urist McDwarf with 18000 exp as a hammerdwarf should have, say, 6000 exp as a macedwarf, making him Adept.
Furthermore, a dwarf should learn more quickly in a particular skill if he is highly experienced in related skills. For example, say I got a fey mood and am now have a legendary metalcrafter. After a season or so of making spears and crossbow bolts, that dwarf should be learning more quickly in Weaponsmithing than Urist McSoapmaker if I had him doing the same thing.
In Summary:
-Experience in a particular skill should contribute to experience in closely related skills up to a cap.
-A dwarf should level faster in a skill if he is very experienced in related skills.
Although this may be seen as unbalancing the current experience system, by reducing the base rate at which dwarves level, it would even out while making the system significantly more realistic.