Currently, developers have to:
I would like to be able to see, at least, the number of reviewers assigned to a task directly from the Scrum Board cards in Jira as this would be much more efficient than going through each card in the "In Review" status (there may be 20 issues at any given time). Developers would only care about those issues with less than 2 reviewers, so that they can jump in.
How can I achieve this? Thanks a lot for your help!
What you try to achieve (as far as i understood) is already available but depends upon the Jira version and the version of development tools connected with Jira. Please see e.g. in the official doc: https://confluence.atlassian.com/jira/viewing-the-code-development-information-for-an-issue-445186939.html
Trying to sum things up:
With incompatible or just older versions of development tools (like FishEye/Crucible) or incomplete configuration in Jira you will only see 'Source' and 'Review' tabs which will not provide you directly with the informations you want. In newer versions and with full integration, Jira does enable a 'Development Tools' panel. Clicking on one of headlines will provide you e.g. with status of reviews and the reviewers within (screenshot: https://confluence.atlassian.com/jira/files/445186939/jira-issue-devpanel.png)
