Sacks count the same no matter which side they come from. Same with pressure.
Adrian Peterson and Marshawn Lynch have more impact on their teams than any CB you can name. Does that make HB a core position?
The only thing that the bold proves is that there currently aren't any elite RTs in the NFL. Which would negate the point you made earlier about it being an easier position to find.
HB a core position? Depends upon the offense being run, I guess. That said, the Vikings won as many or more games without Peterson last year than they did in 3 of the last 4 prior seasons.
But, I won't go back and forth with you on this one. If you have a chance, ask any NFL personnel guy what the core positions are and see how often RT come up.
BTW, I never said it was easy to find elite RTs. I said good RTs. There's a difference. I then qualified my view with my very next post. In the end, if a team valued the position as highly, they wouldn't put their best OT on the blindside. But, IMO, because they don't, there are a lot of good LTs in the league that could very well be elite RTs. In fact, the Rams just cut one due to injury.