I use the same set up as darkmere, and never had problems either. As for line of sight being the determining factor for stationed troops, I have my doubts. In Adventure mode, have traveled across landscapes in flat areas with companions, who only seemed to rush off after wildlife , yes in their sight, but at a certain range. Range seemed to be max bowshot range at archery targets.
They behave the same way caravan guards do, if this makes any sense. As for not reloading bolts, check to see if the bolts are designated CT, not just T. Look at dwarves quivers at the archery range, after they quit firing at the target. If bolts are designated T, they will not immediately refill their quivers. If they are CT they will reload.
Another problem with reloading is the bolts allocated to hunters. You might have 200 bolts in storage, and allocate 200 to that squad. If its a 4 dwarf squad, will load 25 wooden bolts in their quiver, 5 if bone). With 100 bolts being allocated to hunters, after they fire off a volley at
the goblins, and since the remaining bolts are allocated to the hunters, they quit firing, and stay at station as melee dwarves.
Latest experiment is to find reaction distance for dwarves on patrol, station, and defend burrow. Another test is to see what order they chose bolts in, whether by value, position in list, or material. This could influence whether they decide to re-arm, especially with several ammo bins scattered out. I think each stack of bolts is a single item when they decide. Say you assign 100 bolts, whose material is wood, but made from pine, cedar, oak, beech. You then make a separate ammo stockpile, which contains 4 stacks all made of pine. Will the archer go to the original stockpile, and grab the stack of pine bolts, or since the second one also contains pine, will the archer go there?
Final advice, if you have a version with the Armorer as a noble, upgrade to a version without one. Armorer causes delays.
Best advice is that if you have 500 bolts made for combat, assign all to a squad, if you have several stockpiles spread out. If you have walkways behind fortifications on walls, assign all the walkways as 1 burrow, and give the archers a defend burrow alert. Defend burrow is similar to radar. If a dwarf is loitering on the south side of the fort, and goblins appear outside the north wall. Dwarves with that order will rush there. Fortifications fool dwarves into thinking they can path through them. When the fortification halts there movement to the target, they unload on them. Stationing is bad behind fortifications. Since they all do not stand on the same spot, their line of sight can be blocked to the target. As stated above, go to adventure mode, and visit a old fort, with fortifications, and windows, and see for yourself their line of site