All of the right backs you've listed are right backs.
Great defensive record is fantastic - we were atrocious going forward as we had no width. It's 2025 and 4 CBs across the line leaves you toothless upfront, as evident by the past ~4 years.
Also "we had a great defensive record" when we had a full back and then a winger as a second full back sitting on top of each other either side - if we didn't have a great defensive record we might as well stop existing. That said, the record was actually better under Moyes as well, and we played actual football, or tried to at the very least.
So yes, 30 years ago maybe it wasn't that important - however, since the 00s - from the list, Hibbert was great in defence and provided crosses from deep, Neville was a filler in every sense of the word but did an okay job and Coleman spoiled us all by being consistently great for years until the leg break.
We just never replaced him at all, not effectively, not any way, and this "it's not important" is bizarre, as him and Baines were our most important players for about a decade, providing goals and assists consistently. "It wasn't problematic" because we had genuinely good to world class players there for decades and you overlooked it, is what I'm getting.