Collaborative Sequencing (CoSeq) is the process by which a group selects and arranges a set of items into a particular order. CoSeq is ubiquitous, occurring across diverse situations like trip planning or course scheduling. Although indicating preferences, communicating, and consensus building in CoSeq can be overwhelming for groups, little research has aimed at effectively supporting this process. To understand the design space of CoSeq, we ran a formative study to observe how participants utilize visualizations to strategically reduce their cognitive burden. We derived a novel design to enable sequence comparison using visualizations and evaluated its effect through a study. We found that attitudinal measures for the efficiency and effectiveness of the consensus building process were significantly improved with our design.