I preferred -1 Trident, +1 Stone Pillar. This is a first for me seeing this deck, I don't imagine many people have thought to combine Graboids + Trident, and it's difficult to make the trio work well. I think you pulled it off well.
*Edit* In an ideal world I would say to add Reverse Time, but I think it would be hard to find a place for them without weakening the deck or affecting draw consistency.
