Oops. I made a copy and paste error. The line of code needs to start with "perform".
Code:
perform hero.childfound[skFighting].setlinkage[attribute,Attribute,"thingid.attrStr"]
Also, you should get rid of the timing requirement. And I'd probably feel safer putting the overall timing at Setup/1000 instead of at the start of the Pre-Traits phase.
Sorry for the error in the original post.