Uktabi Kong I could be more gung-ho about this card as I was ages ago, but even a green section of a cube thats going deep into supporting ramp doesnt really need Uktabi Kong in a world with Terastodon, Woodfall Primus, and Craterhoof Behemoth
I won my first round of Modern with a mulligan to five, Spell Snare your Tarmogoyf, and cast Blood Moon performance and proceeded to defeat Abzan in game 3 with a very good Delver of Secrets aggressive draw
Additional Notes
Muldrotha, the Gravetides high casting cost and ability to play a land from your graveyard each turn synergizes well with Command Beacon
opponents sacrificing their blockers means that without trample, you wont gain the life
Unlike Crashing Footfalls however, Primeval Titan has been around for many years already, has seen play in multiple other decks in the past (Scapeshift and Titan Breach) and is still kicking strong as a Tier 1 contender despite multiple bans (Summer Bloom, Field of the Dead) in the past