Yea, i didnt realize when writing that formula that it might be the case that the level factor could be wrong or at the same place (The “*defender_level/100” probably shouldn’t be there… maybe).
However, i wrote in the topic where i posted that formula that this is only a theoretical formula without any proof done and just a try to simplify the extremely convoluted formula from the TOS mechanics compilation.
If anyone else wants to try to simplify, correct or prove that formula, feel free to do so. 

Sorry, I mixed it up. Yeah, pierce, which swordsman class has a lot of, and nearly all archer builds do.
Others that you’ve mentioned are still a PIA to deal with, especially when combined.