I'm testing a new mod of my own. I added 15 new species of "morphs" like "cat-morph" and "fox-morph" and whatnot, using a very simple "apply creature variant" style and a lot of copy-paste. This results in humorous situations where 9 trade caravans arrive at once and the turkey-morphs disarm themselves instantly because birds don't have any [GRASP] for their spears.
It also means I'm getting upwards of 400 hostile units on-screen at once. I trained up one soldier to super-legendary status via months in a danger room. She is Super-Dwarvently-Everything now, and +5 in dodging, shield use, armor use, and trance abuse. I sent her out in fine steel to face the hordes, hoping that they would come slightly staggered enough that she would be able to hack down one in an instant, and then the next would approach, and she would never be overwhelmed because she would mow them down too fast.
So, into battle, every hit she delivers hacks off a limb. Every, single, blow, and a moose-morph loses a leg or an arm. A trance, and 5 of them die in an instant with severed heads and arms flying. It's glorious. Then the rest of the 300 troops arrive, and she's overwhelmed, slowly... After several minutes of mind-numbing combat, she's managing to dodge every strike, get in her own blows, and deal significant counter-attacks (which take off limbs). Until, finally, she gets tired, and the crushing weight of a horse-morph spear finds its way through her ☼Steel Helm☼. I was simply amazed at the amount of time it took to bring her down and the amount of damage she did.
I'm trying to bolster my defenses with 5 additional super-dwarves, but the going is slow as I'm smelting iron now and the FPS drag is enormous. I'm going to need to scale back the siege numbers a little... 25 dwarves and I've got my FPS meter turned off, but I'm guessing somewhere in the 15 range.