Can you add the userrights to a group of bureaucrats in hewikisource?
No, since userrights allows unlimited access to restricted groups like steward/checkuser/oversight. If there's community consensus to allow someone to add some specific groups please see https://meta.wikimedia.org/wiki/Requesting_wiki_configuration_changes - thanks!
Hi yisrael12, we'd like to note that Wikimedia Phabricator is for bug reports and enhancement requests (for example changing the site configuration). For general support questions if something is possible, please ask on https://www.mediawiki.org/wiki/Project:Support_desk or https://meta.wikimedia.org/wiki/Tech . To request changes on behalf of a community, please follow https://meta.wikimedia.org/wiki/Requesting_wiki_configuration_changes . Thanks for your understanding!