I'll throw in an alternative perspective: I don't care so much about expertise, but about just raw intelligence. Talk to a really smart person about your engi

I'll throw in an alternative perspective: I don't care so much about expertise, but about just raw intelligence. Talk to a really smart person about your engineering problem, and even if they are not an engineer they will give you good advice. Ditto for sales, marketing, etc. I've always been happy when I can tell the person that is managing me is a few steps ahead of me, allows me to learn from them and actually makes my job easier. To me, it's only a bonus if they can do my job better.