After trading this guide, I attempted to steal from Bronze for about 3 hours, which is at least 20 failed attempts until I rage quit and fell asleep. Woke up next morning irl failed on 3 bronze quads, then just walked up to a silver quad and steal was successful. I didn't engage it first, just ran up to it, stole from the side of him (not in back).
I really don't think any positioning matters and everything is pure luck.