Golgari Midrange leans on graveyard-based value, most notably Deadly Cover-Up's evidence collection, which exiles and strips cards from hand, hand, and library, so Rest in Peace denies that value and protects our creatures from being permanently answered by their removal-heavy plan. Seam Rip is efficient at exiling early problem permanents with mana value 2 or less before they can develop, though it's too narrow to answer a threat like a resolved Professor Dellian Fel. Burst Lightning struggles against their higher-toughness threats and removal-dense list, and Erode is redundant with our other removal that already handles their creatures and planeswalkers, so both get trimmed. This preserves our full mana base and core threats while adding targeted disruption against their grindy, attrition-based game plan.