Very glad to see someone's working on testing melee weapons! In particular, I am curious to see if protection from melee weapons follows the same mechanism as ranged weapons. Specifically, we find that armor protects 50% of the time if bolt momentum = (IMPACT_FRACTURE-IMPACT_YIELD/2)*round(contact area * LAYER_SIZE) / 2250000. "Protection" means that the attack is either deflected or results on only bruises. Fracture and Yield refer to the armor material, contact area the weapon, and LAYER_SIZE the thickness of the armor. The rounding function give 100 for numbers less then 100, and floors to the nearest 100 otherwise (i.e. 250->200, 875->800, etc). This result is for Great archers/marksdwarves, and grand master armor users. The denominator appears to change somewhat for different skill levels, which is my current line of investigation. I suspect that maybe melee weapons will follow the same behavior with momentum calculated as weapon mass * velocity multiplier.
I suggest, in addition to using Zivilin's arena dwarves (which I think you already found) you consider using Urist Da Vinci's uniarmor:
[ITEM_ARMOR:ITEM_ARMOR_UNIPLATE]
[NAME:uniplate:uniplates]
[ARMORLEVEL:3]
[UBSTEP:1]
[LBSTEP:2] lower body now protected once
[SHAPED]
[LAYER:ARMOR]
[COVERAGE:100]
[LAYER_SIZE:20]
[LAYER_PERMIT:50]
[MATERIAL_SIZE:9]
[HARD]
[METAL]
[ITEM_HELM:ITEM_HELM_UNIHELM]
[NAME:unihelm:unihelms]
[ARMORLEVEL:1]
[METAL_ARMOR_LEVELS]
[SHAPED]
[LAYER:ARMOR]
[COVERAGE:100]
[LAYER_SIZE:20] alter this to change "thickness"
[LAYER_PERMIT:20]
[MATERIAL_SIZE:2]
[HARD]
[METAL]
[BARRED]
[SCALED]
[LEATHER]
[SHAPED]
[ITEM_SHOES:ITEM_SHOES_BOOTS_UNILOW]
[NAME:uni boot:uni boots]
[ARMORLEVEL:1]
[METAL_ARMOR_LEVELS]
[LAYER:OVER]
[COVERAGE:100]
[LAYER_SIZE:20] alter this to change "thickness"
[LAYER_PERMIT:15]
[MATERIAL_SIZE:1]
[METAL]
[LEATHER]
[HARD]
[ITEM_GLOVES:ITEM_GLOVES_UNIGAUNTLETS]
[NAME:unigauntlet:unigauntlets]
[ARMORLEVEL:2]
[UPSTEP:1]
[SHAPED]
[LAYER:ARMOR]
[COVERAGE:100]
[LAYER_SIZE:20] alter this to change "thickness"
[LAYER_PERMIT:15]
[MATERIAL_SIZE:2]
[SCALED]
[BARRED]
[METAL]
[HARD]
If you need any help with modding or testing, don't hesitate to contact me. In particular, I have scripts for analyzing gamelog.txt to find rates of deflection, bruising, etc, that would likely be very useful to you. I have to go now, but if you're interested I can post those later. There is an old version on DFFD linked somewhere in our crossbow testing thread too, but that's quite out of date.
I also plan to do some testing of bolt and armor quality by the end of this week. Urist write me a DFHack script to change qualities, and I just need to get my lazy act together and implement it inside of my testing code. I will let you know what I find, as I imagine there will be parallels.