Again....everyone has opinions. And yours is as valid as anyone else's (well, except for guys like "21" and Sluggo - who spew their nonsense without any reasonable basis wrt a "better solution"
)
FWIW, I agree on Mahon playing a lot better at RT than he did at OG (mentioned as much during the season, when I was breaking down each game). In fact, if I looked ONLY at his time at RT, I might very well agree that he was better there (at RT) than anyone else was at any other position.
Unfortunately, he only saw a small portion of his PT at RT, large majority at RG. Alas - but they had to try to field the "best 5" out of what was available.
Nelson? Just MHO, after his injury he was getting his lunch eaten (prior to the injury, he was pretty effective, but that was only a couple of games out of the season). If so, not his fault, for sure, because he was clearly out their "gutting it out" at well under 100% (IMO) because there just were not other options.