I noticed you have them in leather, is it a problem to have them in metal armor? I'm training mine up as legendary hammerdwarves as well for when they inevitably get into melee, but I can't seem to get then into steel.
I've run into the same issue, and haven't found a way to fix it (I'm *just* starting to ramp up metal production in this fort, so it will be awhile before I have full armor sets). I always have dwarves train in leather; having them in iron and steel without armor user slows them down so much they become walking targets and thus actually makes them weaker.
My guess here is because the quiver goes on "Upper Body", its conflicting with one of the upper body metal slots; my guess breastplates.That or the idiots are equipping themselves wrong. I generally use fortications and patrol routes with marksdwarves to prevent them from getting in melee in the first place since crossbows suck as melee weapons.
Your sig, this... You might just be the greatest dwarven military commander of all time. I'll be sure to give you a good place in Murdermachines' ending.
I just sent you a PM with details of what my dwarf did in Deathgate, and what I was planning to do with her story before RL got in the way.
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On another note, I just realized this method might fix ranged dwarves charging into combat. They won't increase their discpline very high with this method, and that means they are MUCH more likely to avoid rushing in once their bolts are discharged. Once they break line of sight with an enemy, they'll go get bolts to reload.