I don't mean to minimize anything those guys do in real life, but as far as the TV show goes, I agree with you.
I backpack a LOT in Shining Rock and surrounding area, and while even at that, I wouldn't consider myself any expert on the area, but I'm pretty familliar with a lot of it. My family is from the Balsam Grove area (the other side of the Pkwy on 215 towards Rosman.)
I told my wife that their "mine" (on one episode) was obviously on Flat Laurel Creek, and I truly hope nobody else recognizes it and thinks it's full of $10,000 Sapphires, that'll be the end of the area as we know it.
And, when they were on their "25 mile journey", you could plainly see in one scene, the twin peaks of Sam Knob and the grove of fir trees indicating to me they were standing right AT the Black Balsam parking lot gazing across the valley (of Flat Laurel headwaters) toward Silvermine Bald and Mt. Hardy...less than a half mile from the Parkway...and probably 25 yards from that parking lot.
I'm sure anybody who's been up there a few times and saw the show noticed the same thing.
The notion, though, makes for good TV I reckon'.
And say, doesn't that other fella' (the older one) seems to enunciate in somewhat of a "Northern persuasion" to you?
Just sayin'.