I'm sorry but this system is far too complex, I gave up trying to understand it halfway through. There must be a simpler way of remembering.
I need a real simple system so I had an idea:
ABCDEFG = A-Big-Crocodile-Does-Eat-Fat-Greasy-Homeless.
1: Bun, 2: Shoe, 3: Pea 4: Door, 5: Apple, 6: Bricks, 7: Heaven, 8: Crate
So C8 could be Crocodile Crate. As everything is a picture combo upside down doesn't matter. You just visualise each row and column with a picture. Idk.
Given the context, I'm having trouble pronouncing "5"
I don't know of any good nouns that rhyme with five. Maybe "hive"?
Play tic-tac-toe, it only has 3 rows.