Random assignment makes groups alike on average. Still check assignment logs, eligibility, sample-ratio mismatch (unplanned group sizes), outcome coverage and the planned analysis horizon. Analyse outcomes by original assignment for an intention-to-treat effect. Dropping failed deliveries after assignment can leave different kinds of customers in each arm.
The comparison also needs a clear action and outcome, a real chance of receiving each compared action, and a design for any interference or carryover (lasting effects of earlier actions). Randomising one customer's price may change another's demand or use up shared stock. Choose the assignment unit and interpret results accordingly.