Hriston
Dungeon Master of Middle-earth (He/him)
Here's an interpretation of the Gygax article your bringing up again.
This quote I took from the Paizo forums
This wouldn't be the first time someone was unable to understand Gary's prose. I mean, it isn't called Gygaxian for nothing.
My take is that at no point in the article does Gygax say to use player knowledge but he several times says to makes decisions based on character knowledge not player knowledge.
I think the issue of player-knowledge versus character-knowledge is not addressed by this article. Gygax says players should rely on the skills of their characters to solve problems, but he doesn't say anything about characters relying on the skills of their players. To me this is a non-issue. The character makes no actual decisions at the level of metagaming and has no access to the knowledge of the player in making fictional decisions. If a character just so happens to know something a player knows, there is no reason to assume the character learned it from the player. The character has fictionally acquired that knowledge elsewhere.