Just throwing my opinion to the original suggestion:
First of all both tasks, engraving and stone smoothing, should use the same skill. This would keep it relatively easy to have legendary engraver (or even grand master). If those tasks use different skills it would be nearly impossible to have a legendary engraver outside the moods.
Now, what I suggest is to separate the two tasks in terms of labor; while the skills is same for both labors each one must be enabled separately. Do you want to have legendary engraver to smooth out that quarters dedicated to king while those who are still training the skill keep on smoothing the halls? Just enable the engraving labor for the legendary dwarf and disable it from rest of the dwarves. They still keep on smoothing stone as that labor is separated from engraving, thus disabling engraving doesn't prevent them to smoothing stones.
Another thing where this has some uses is when tapping to either underground water source or magma; currently all dwarves who have the stone detailing enabled are candidates to carving the fortification, thus risking their lives. If you want to avoid risking your legendary dwarves then just disable the smoothing labor from them and they can still keep on making those engravings.
Agreed. I would have posted more or less the same thing if no one else had (although I didn't think of the fortifications thing).
-snip-
I also support merging of some skills. At the very least there should be synergies (say effective skill = max {skill, max{similar skills}/5 }, so a legendary cheese maker would have automatic 3 in milking. Well, maybe 5 is too conservative, and 2 would be better, or between 2 and 5 depending how related the skills are)
Sensible. It would cut down on the number of completely useless migrants.
* Crossbow-making should be split between carpentry and bone carving (but maybe keep the bowyer's workshop). If you even use marksdwarves, they usually get metal crossbows (made with weaponsmithing, which you want to train anyway). There is never need for enough wood / bone crossbows to justify having a bowyer. Arrows should be made at bowyer's workshop, tough.
"Never need for enough wood/bone crossbows to justify having a bowyer?" I heartily disagree. Making ammo should probably fall under bowyery, though.
* Mining skill is useful for combat, but wood cutting isn't. I propose merging Wood cutting and Axedwarf.
Not sure about merging, but having heavy synergy between the two I could see.
* Animal Care, Shearing, Bee Keeping and animal training
Also animal caretaking.
* Trapping and small animal dissection are pretty useless.
Yeah, I guess. Trapping could be merged with hunting, perhaps, and small animal dissection (as well as fish dissection) could be merged with fish cleaning or butchery. Or maybe all four skills could be rolled into one.
* Tanning might be merged with either butchery or leather working.
Probably leather working. Of course, since the tan hide reaction is in the raws, someone's going to point out that you can change it.
* Wood burning merge with Furnace Operating
Seems reasonable, unless...
* Soap making / lye making / potash making - these skills are not often used, and require separate workshops.
Probably lye- and potash-making should be rolled into one skill, possibly under either wood burning or soap making.
* Milling, Pressing, Plant processing, Wax Working
Not sure about wax working (which might be similar enough to pottery without the fuel to justify moving the
one wax-working reaction to pottery), but since the rest are just different ways of squishing stuff, it's sensible.
* Plant Gathering and Farming
Makes sense. Usually, my planter is also an herbalist.
[quote[* Milking and Cheese making[/quote]
Makes sense.
* Spinning and weaving and separate labour to collect webs.
Yes, makes sense. Maybe a new hauling labor (web gathering), or maybe just an extension of whichever hauing labor it is to haul woven thread.
* Fishing, Fish Cleaning and fish dissection and prioritize fish cleaning over fishing.
Not sure about mixing fishing with the other two, but see above.
* Blacksmithing, Metal Crafting
If carpentry and woodcrafting, or masonry and stonecrafting, are kept separate, so should blacksmithing and metalcrafting.
* Gem Cutting and Gem setting - keep separate labours, but merge skills for easier training of jewellers
Maybe...
* Wood crafting and Carpentry.
You left masonry and stonecrafting off. As long as those are separate, woodcrafting and carpentry should be too.
* Pottery and Glazing
Sensible.
* Siege engineering and Mechanics
Might require a broadening of what mechanics covers, but not by much. Sensible, overall.