I always bring along some proficient armorers and weapon-smiths so I can make the most of my metal. Since my miners have 5 extra skills points I don't otherwise use, I have them as my alternate armorers or weaponsmiths.
On my latest fort, where I'm building a shaft-style fortress and flattening out the surrounding terrain to turn it into a great big natural-stone tower, and putting up with the intensely laggy ramping process to remove the surrounding stone. The ultimate goal is to have the map be laid out like a giant crater, with the tower starting at the deepest point.
Things are mostly going along well, I managed to safely route magma into the side of the tower and get my magma forges going. Only found copper so far, but my military of 11 should be pretty decent with their well-made or better copper crossbows.
Unfortunately I haven't used them as well as I should. Both my main armorer and my alternate-armorer miner were killed by a single, weak goblin ambush. Five goblins, mix of wrestlers or lashers, no experts. Despite one of them being a legendary miner and the other being a near-legendary mason and both being proficient armorsmiths, they were annihilated before my 6 elite wrestlers / marksdwarves could rescue them.
WTF :*(>
edit: OH! Turns out I forgot to deactivate my miner-armorsmith, so I still got one. Phew. Unfortunately my best mason is down for the count, but I guess we can start pumping out blocks so we can get nice new furniture again.