I made a real super soldier program. You need a volcano.
First, give them a barracks, and let them spar, but make sure that every tile is covered in 10x Training Spears. Between that and the normal training they should level up quickly.
Next, you want to get them armoured. I had tons of copper, so I just had my Talented Armorsmith make Copper Mail Shirts all day, and then they'd either be melted down back into Copper Bars or sold to caravans for booze/food (I produced none, but had a large stockpile). After years, and a Copper Boot covered in gems, he was legendary. Same with the Weaponsmith, although that's not as important.
Then, I dug deep enough to hit Granite and mined out the whole layer until I got tons of Cassiterite and Bismuthinite. Now, I'm playing a more realistic version where Iron is called Wrought Iron, and is inferior to Bronze. Old version Steel > Iron > Bonze. My mod version Carbon Steel > Bronze > Pig Iron > Bismuth Bronze > Arsenical Bronze > Wrought Iron.
I had my Metalsmith make suit after suit of armour, and anything that wasn't masterwork was melted down and reused to make another suit. After some time, I set up a leatherworker to make clothing for my dwarves: I don't think a hair-covered dwarf would like to wear chain with nothing under it. Just being considerate. The Naked Mole Dogs I had been breeding were slaughtered for their skins.
Armour: Masterwork Bronze Helm, Leather Hood, Leather Shirt, Masterwork Bronze Chain Mail, Masterwork Bronze Chain Mail, Masterwork Bronze Breastplate, Leather Robe, Masterwork Bronze Gauntlets, Leather Pants, Masterwork Bronze Chain Leggings, Masterwork Bronze Greaves (modded leggings to be non-fitted), Leather Long Skirt (don't judge: it helps), Masterwork Bronze Chausses (sockmail, made it uncommon for dwarves and got lucky), Masterwork Bronze Low Boot (not so lucky here but whatevs), Masterwork Bronze Shield. On top of this, they still ran faster than civilians.
Finally, for weapons, I asked the caravan for steel bars, steel anvils, and steel flasks. Smelted them down and made Masterwork Steel Spears.
Unfortunately, there was no Adamantine on my map (well, like, two levels, but I'm fairly sure that would've opened up the circus).
Now, I had two suits for the. A Training Suit, and Battle Armor. Battle Armor was posted above. Training Armor was a Bronze Helm, Leather Hood, Leather Robe, Bronze Breastplate, and Bronze Gauntlets. Why? Because some of the training spears were replaced with Copper Spears (not made by the masterwork weaponsmith). The dwarves almost always doged them, but occasionally would get cut and rush over to the well-stocked hospital nearby and get sown up. After a few more years, they had more scars than an emo kid, but still never got killed. Toughened them up and kept the Doctors in shape.
Then, a goblin siege showed up. I put them all in their battle armour, and opened the gates. The Goblins rushed in, the dwarves rushed out, and it was over in like 5 seconds. I lost 0 out of my 20 soldiers, no goblin survived. I just dumped it all in the magma: I had no use for a crappy Wrought Iron Scimitar.
And yes, teaching/leader/student helps a lot.