Subnet Sizing
I think a subject for the design clinic can be subnets design (sizing/population). I’ve wrote a blog post on pros and cons of big/small and heterogenous subnets:
https://netmemo.github.io/post/subnets-size-mix/
This is to argue for swimlane application and prevent L2 stretching. Maybe the blog can serve as a starting point. I might miss some points or maybe it would be better to split it into physical/virtual/cloud.