Oooooh, this list is SAUCY! I love this all-in approach. I definitely need to test this.
I actually think that a deck without blue can still have game against Combo. Thorn of Amethyst is SUPER powerful against any sort of combo deck, and don't forget we can still run Chalice of the Void for huge value. There are many colorless ways of shutting down combo decks.
Something I've been really thinking about lately is trying to play through control decks. I feel like there are plenty of lands out there that can allow us to power through control at huge value, and if we are going to run Explore, Map, AND Crop rotation, I think there's a place for them in there.
I've been testing a single copy of
Cavern of Souls to great success in order to consistently resolve my Primeval Titans, and if we're seriously looking at TtB, I think there's room for
Boseiju, Who Shelters All somewhere in the 60. Maybe it belongs in the sideboard, I don't know. All I know is, protecting a TtB seems really important. That card can win a game immediately.