Regarding the chess symbolism in TG. Arima being cast as the white knight would make sense. His tie pin was a horse and the knight pieces in chess are usually horse heads
What’s a bit amusing is that Arima is casted as a knight in the CCG a couple of times; (1) TG Jack, (2) during the first SC Meeting, (3) his name (tho to be picky, his name could contain both Knight and King), and (4) the tie pin he received from Haise.
Originally a Jack of Spades, he turned into a (black) Joker in the trump cards and Eto (and Tatara) titled him as the One-Eyed King.
I personally still see Arima more as a Knight rather than as a King in terms of chess as well since Arima seemed more like someone who got ruled over rather than doing the ruling himself (and tho limited, Knights move better). But overall, I feel like he did manage to take on both roles!
There’s also this one time where it appeared like he had a IV on his back which would make you think of the Emperor arcana.