Communication skills are paramount. Analytics are par for the course. However, communication skills are critical success factors for any position in finance (or other professional services roles).
We always encourage students to know more than the analytics, and to be well versed on the industry and nuances of the field. The reason being, it is a highly competitive world. The more you can make an interview conversational and feel natural (aka organic), the more that will help differentiate you. The last thing you want to do during an interview, is feel like you are on your "heels" or the "ropes". The goal is to exhibit your understanding of the industry and showcase your capabilities, while also, being likable.
This same philosophy is the foundation for helping manage client relationships (banking, equity research, LPs at a PE fund, C-suite in corporate M&A) as well as the buy-side (nurturing relationships with targets, company CEOs, LPs at a PE fund, other investors).