Whatever artifact makes sense. Maybe a spreadsheet list. Maybe a one page, or half page, serious coherent characterization from each person.

How people independently see priorities before collective discussion, being as important as how they rate them, I would go with one page thoughtful summaries.

Having experienced partially-aligned organizations, I would want key contributors to a discussion like this to come from every major part of an organization. Emphasis on very different roles, especially important leaf roles, not just top leaders. Otherwise you get high bubble-at-the-top alignment. Top-only strong alignment is like concrete, perniciously inflexible. Which is what I experienced. End-to-end insight and discovery of alignment is needed to get adaptable, in-touch, actually effective alignment.

And as is hammered so well in "Creativity, Inc" by Ed Catmull, alignment isn't just about coordinating efforts. It is about continuously identifying and removing friction, of any kind, anywhere, for anyone, as individuals make their very different contributions in service to the common direction.

aka Arrow's impossibility theorem?