Scion of Murgen (He/Him)
I was in part just offering it as a counterpoint that any weapon vs. ac system would necessarily look like the Greyhawk and 1E ones, but yeah, I think Delta's first crack at it doesn't quite work.Chain was Excellent against slashing attacks, not just "Good". It was certainly better than Leather.
In short, heavier armor was generally simply "better", but according to the table above Leather is the best overall with two Goods and an Excellent. That alone tells me this is not a realistic system at all. There might be more to it I am missing, but those are my first thoughts anyway.
Did you check out Matthew's points in the comments? I like his ideas, though I'd be inclined to bump his suggested +1s to +2s, because I agree with Delta that +1 bonuses are a little too small and fiddly to really bother with.