Yeah, it's definitely highly dependent on the situation. Based on my limited experience with how penalty areas are marked near cart paths, it's very rare to see the relief area be between the cart path and the penalty area. That's why I was skeptical but also hedged in my post.
In any event, this is really an easy situation in competition. Have them play 2 balls and take some pictures of the area. Let the committee sort it out afterwards. That's easier than arguing about it and have that hanging over your head.
The Relief Area must be in the General Area, but that doesn't apply to the area of stance and swing. As an example, consider a cart path down the left side, with 2 feet of grass between the path and the Penalty Area. A ball is on the left edge of the path, the NPCR is a few inches off the path towards the PA (for a right-handed player), and his resulting stance might be in the PA. His area of stance and swing is free of interference by the cart path, even though he'd be standing in the Penalty Area to hit the shot.
I've mentioned my story as a "Range Rat" for a year before- Dad would go and play and he would leave me at the range to learn the game. It worked- the first round was a 98 (13yo). And beat him by 6. I think later on he was annoyed AND proud at the same time. I never shot over 100, and he never did beat me. 4 years later I could shoot par maybe once a month with those original Northwestern Chi Chi Rodriguez Blades (half set- 1,3,5W's, 3,5,7,9, putter) I started with.
That's how you learn to center it and play all those in between shots. Learn on a half set of butter knives.