I think that's a problem where you don't have well-defined ladders, so there's no "obvious" way to distinguish newgrads from greybeards. There are lots of team

I think that's a problem where you don't have well-defined ladders, so there's no "obvious" way to distinguish newgrads from greybeards. There are lots of teams at Google where an L6-7 manager has reports who are anywhere from L3 to L7; this, in fact, has been my experience the entire 5 years I've worked there. This shouldn't be a problem at all, and hasn't been in my experience. I have, in fact, been in exactly the situation where I'm mentoring a new-grad who is assigned my subteam. I'm the TL, but not their manager, so the relationship and responsibility is very clear.