How the f am I expected to get a fully functioning military capable of clearing entire waves of goblins in under two years without using danger rooms?! Especially when I have no native iron ore, and every civvie for the first two waves is needed for some kind of masonry or farming. ESPECIALLY when my most promising military dwarves get wrecked by a giant bat in the caverns on the first year.
Up point to around 2000, bring coal, lots of it. Bring a weapon/armor smith and a minimum of one soldier, with a weapon. I personally go for dodge, armor, shield, and novice with the weapon so they can train recruits in these important areas while until recruits arrive they should be able to face most early threats if provided with a wooden shield (wood shields do the same job and are a hell of alot lighter, keeping this currently unarmored dwarf light on their feet.)
Most important factor here with arms and armor production is be willing to settle on copper and bronze until goblinite starts rolling in. Copper weapons work just as well on most things, though megabeasts may have skulls to thick to slice or stab through with copper, bronze, or even iron. I personally eschew melting of items simply because I need the coal for more important things and just jam the weapons in traps at certain chokepoints. Makes a world of difference when the enemy officers get mulched when they try to take a corner. One last thing to note is enemies tend to prefer only the bare minimum of protection, meaning copper weapons will often take off limbs in skilled hands. Plus the surplus of old weaponry means in a pinch, everyone can be armed with
something, which is a hell of a lot better than going into battle barehanded.
Make sure your military dwarves are training constantly as well; for those legendary melee goblin grinders, their training must be unending and unmerciful. Just provide good food, booze, a nice dining room to eat in and good bedrooms and that will mitigate unhappiness. Squads of 3 are my personal preference, and often times 3-9 legendary soldiers are all you need to chew through most threats like they don't exist. Backing this up with part-timers (lightly armored speardwarves seem to excel in supporting more heavily armored swordsdwarves for instance, though the light gear does mean they have shit staying power in a major battle,) or a massive crossbow levy can result in the enemy's assault falling apart before your eyes as soldiers and mounts get pegged with bolt after bolt, resulting in incapacitation.
If your best candidates drop, bear in mind any dwarf if given a year or two can go from a weak, piddling fish cleaner to a sword or axe wielding boogeyman that haunts the dreams of goblin soldiers everywhere.