It would be great to allow a VP of Sales to be a reviewer and have control of the "Sales" section of my scorecard. If you take that logic and expand, I could have Services / Support / Marketing all managing their own scoring, but still control the formula to create overall value for ideas and features. This would make Product Management more efficient by allowing teams to interact directly.
Currently, scorecard values can be edited by contributors and product owners. As you may know, reviewers have capabilities around to-do's and commenting/reviewing records in Aha! We've spent a lot of time crafting these roles based on feedback from the community.
One potential workaround would be to have your VP of sales to stay as a reviewer and "comment" on the Sales score for that value. Or you could upgrade his permissions to a contributor role.
At this time, we do not have plans to make changes in this area, but hope that the noted workaround can potentially work for you. We hope you can understand.