You're planning to accumulate kills in a controlled environment and you think he'd be comparable to Tholtig?
You obviously don't get the idea of this project. It's not about being "better" than Tholtig. If you would actually read the opening post, you'll see that there is not a single phrase indicating something about being "better" than Tholtig.
It's about getting more kills. Nothing more, nothing less.
Let's recall, Tholtig wasn't an in-game dwarf - she was a historical figure that got produced during Worldgen. There's no telling whether or not it's even _possible_ to accomplish what she did during gameplay. As has been pointed out, the chances of a random stray arrow doing critical damage in game are fairly high over such a long history. I'm going to go ahead and suggest that the combat calculations are vastly simplified during worldgen, which likely contributes to careers like this.
Still, it's certainly an epic project. 2500 is a _lot_ of kills, even if they are orchestrated. I'm inclined to say _especially_ if they are orchestrated, given all the extra time that would take, setting up each kill individually.
Toady actually posted the combat calculations at one point, and I think they're for 40d.
This is only for non-critical melee hits. Essentially, a bad luck roll (note that toughness is factored in randomly, not totally) means that even your badass warrior might get stomped by a kobold (it's just very, very unlikely, and pretty much requires them to go berserk).
Of course, if your toughness is high enough you'll probably survive it. Morul survives being hit by a ballista, which is an instagib on everything from cows to dragons. He regens every wound less than yellow instantly, and is barely hampered by even red injuries. And Morul isn't even the most awesome of warriors, as his creator had to spend a lot of time doing the slow and boring trapping work (among other tedious tasks), so his toughness is only 78 or something.
Get a powerful enough dwarf this version (before attribute caps next version) and you won't die to anything unless you have terrible luck.