> From my experience, I see institutional knowledge as a double edged sword - it can save you from some mistakes but, very often, it's also the thing standing in the way of progress.

I can’t agree with you more. Having a combination of individuals with historical knowledge and new individuals with fresh perspectives can be so refreshing. We recently hired an external architect on the team. She’s great technically. However, I would argue her greatest contribution is fresh perspectives. She suggests ideas others (include me) hadn’t considered due to past negative experiences with team X or Y. By not being as aware of past histories or projects gone bad, she can encourage us to rethink things.