Well, I tried. It seems you can't even move fighters and stickmen the way you move ordinary particles because their .x and .y properties only seem to have an influence on the position of their legs and not on their heads.
The syntax looks very strange, I think it is something like sim.stickmen(, , , ). If you can figure it out, you could probably do this in my mod. Although i'm actually not sure if it is possible to disable FIGH from moving towards stickman at all. Doesn't look like it, unless maybe you can dig into the code a little more. I suggest looking at the FIGH code, it is pretty simple.