Without making it solely about Jesmond and Garden Suburbs, you're words above of "strong case" alone would have to elude to Jesmond, right now, deserve to be playing against Mayfield and Dudley more than Garden Suburbs do. I'm not sure that can be argued with. Do so if you wish.
I honestly don't think it will come to one or the other from the abovementioned teams because of another probable restructure above.
I'd love to know why they continue to restructure the divisions. Sure, have criteria to play 1st division football in Newcastle - Ie decent ground, ability to field a youth team, be strong financially etc.
BUT after that divsions 2 to 6 (and lets just call them that rather than make 3rd, 4th etc division clubs feel special) are straight promotion and relegation. If you're the worst team in division 2, guess what, the best in 3 is taking your spot.
It's not brain science or rocket surgery people!