i couldn't really give less of a shit about northern honor (i think grrm complicates that aspect of them with every book) but goddd the discourse about ned being honorable only because of jon arryn is so annyoing
there's a number of things going on here, one of which is a conflation of honor with being a good person - which are not the same thing. Honor is just an adherence to a code of conduct. Ned happens to be both honorable and good, but what he isn't, is chivalrous. He is very explicitly not a knight, he doesn't act like a knight or talk like one - which is interesting bcs isn't that what Jon Arryn would've taught him if he was really indoctrinating Ned into the civilized southern ways? Robert is chivalrous, at least when he's young - that's why he spares Barristan at the Trident.
In fact he is less chivalrous than his siblings raised in the North - Brandon acts very much like a knight when he repeatedly spares Littlefinger's life and then later when he rides to king's landing to challenge Rhaegar to a duel for Lyanna. Lyanna literally adopts a persona of a knight, acts chivalrously and honorably by defending Howland's honor. Was Jon Arryn sneaking into Winterfell to teach them that?