Such data is included in a file called hireling.txt, that i think can be generated from one of the game files.
It was actually quite a trouble to find that file myself on the web, cause you can come across many different versions (D2, D2R, mods, etc).
I found the one for D2R on a random github repository, saved the file, but unfortunately, didn't save the page at all =[
But if you want to know the action probabilities for another (specific) merc, i could retrieve them for you =]