There have been similar ideas like this in the past, and I do think it would be nice so long as leaders are responsible with who they chose as their "second in command" of sorts.
However, thar be issues with, firstly, that'd be something we'd need the source code to do (just stating the obvious with that one). But I have a feeling that might be glitchy in some ways. Group has always been quirky in that sometimes it leaks arrivals in the group, and adding this might be full of unknown bugs.
That's just speculation, but the idea in itself isn't a bad one. It certainly would be practical if it worked properly.