I started making lists, deleting, changing, and so on, but now I'm not sure I had the right idea at the beginning.
I *think* what might actually be useful is an explicit "(tech) lead" column on our quarterly goal page, eg https://www.mediawiki.org/wiki/Wikimedia_Release_Engineering_Team/Goals/201617Q1 .
I don't think we need a tech lead for every piece of software we maintain. And as I was making lists I realized after the top 3ish things we work on, the rest is group maintained without an explicit owner which is A Good Thing. And at that point, anything that would identify "leaders" for those down-ticket things would end up just being yet-another Skill Matrix.
I'll bring this back up in our team meeting and see if people agree.
(not a column, but just "(Lead)" next to the appropriate name)