Both are random events. Both events should happend with 25 or 50% probability (do not remember precisely)
BTW, I think I have moved the farm gang somewhere to one of the east crossroads. This was done to let you go to the Farm, the area I am working on now (slowly, but stadily).
For anyone else who is having issues with the gang or the thug attacking you, it looks like the thug now attacks you only when walking out of the bar with booze, so if you walk in, buy it, walk out, it has a chance to trigger it. Pour it out if it doesn't and try again.
I encountered the gang of thugs by walking up from the southwest to the northwest corner, so I'm guessing they're currently located in the Northwest end of town.
As a note for Larry, finishing the fight with them drops you off at the farm instead of where they are located!