But it would not surprise me to find that even the Williams-level of bounty promotion was common.
Exactly. Was watching one of those NFL Network shows, list of the greatest whatever whatevers ever (you know, multi-tasking, it's background noise), might have been biggest hitters ever, and they were talking about how this one dude from the 50s was sort of a Lambert-sized guy but whacked players with this shoulder move and basically broke jaws, ribs, whatever. (Think: Hines Ward introduces Keith Rivers to the NFL.) And they were openly talking about teams having a bounty on taking this guy out!
It's been around forever. Whether it's a casual thing with just players, or coaches getting into the act, it's there. But like Golic was saying, in the moment, you're out there to hit your guy and make the play, bounty or no. You're hitting him as hard as you can every time, bounty or no. So it's just a bonus. The line that could be crossed would be if the hit was dirty, and that's always a fine line anyway. E.g., no such as a dirty thing when someone hits Ben; every hit on Beardy is the work of Satan.