Boros Control aims to disrupt your combo with a combination of land destruction (Cleansing Wildfire, Demolition Field, Field of Ruin), sweepers (Wrath of the Skies), and exile-based removal (Path to Exile, Solitude, Erode). Since you're landless, their land destruction package is largely irrelevant, making their core disruption plan toothless — this matchup is heavily in your favor pre-board. Post-board, they bring in Orim's Chant and Vexing Bauble to slow you down, along with Kataki, War's Wage which taxes your artifacts, so Flusterstorm and Mystical Dispute come in to protect your combo through their interaction. Harbinger of the Seas is an effective threat that also punishes their fetchland and nonbasic-heavy manabase, forcing them to use removal on a creature rather than disrupting your combo pieces. Spell Snare and Stern Scolding are cut because their interaction suite is largely mana-value agnostic (sweepers, exile) and these counters have low target density against Boros Control, while Suppression Ray loses value since they're not a creature-swarm deck trying to attack through.