Cards in low res even though hi res cards are in the folders

I am having problems with the arabian nights expansion. When I do a booster draft, some cards are blank, even though they are referenced as 'ARN'. I have all hi res cards in this folder. Yet, it seems to pull them from somewhere else. I thought the game always got its art from the 'cards' folders according to the name that shows up on the forge screen. I could understand it if forge shows 'rukh egg' as coming from 'AN' and I didn't name the folder correctly, but it always shows 'ARN' for arabian nights cards.
second question: why are all the cards also outside of their folders in the 'cards' folder? These are all low res. The game seems to pull low res art from this section sometimes, but I don't know why it would if the cards shows up as 'ARN'. Shouldn't it take the art from the 'ARN' folder?
So, since the game is not pulling card art from my hi res 'ARN' folder, and pulling it from the low res images within the 'cards' folder, I replaced the low res arabian nights cards with hi res art, same name, and then the cards still show up as blanks when I start a booster draft. Example 'hasran ogress.full.jpg'. But, when I change the hi res card name to 'hasran ogress1.full.jpg', it suddenly appears in the game. Why would it need the '1'?
second question: why are all the cards also outside of their folders in the 'cards' folder? These are all low res. The game seems to pull low res art from this section sometimes, but I don't know why it would if the cards shows up as 'ARN'. Shouldn't it take the art from the 'ARN' folder?
So, since the game is not pulling card art from my hi res 'ARN' folder, and pulling it from the low res images within the 'cards' folder, I replaced the low res arabian nights cards with hi res art, same name, and then the cards still show up as blanks when I start a booster draft. Example 'hasran ogress.full.jpg'. But, when I change the hi res card name to 'hasran ogress1.full.jpg', it suddenly appears in the game. Why would it need the '1'?