Hi all, and thank you for your continued feedback. As @Marie mentioned back in May, we appreciate you sharing these use cases and the problems you’re hoping to solve, to help Asana understand the motivations behind this feature request.
Our Research and Development teams were actively exploring these pain points to understand how Asana might enable better visibility and control over resource management and capacity planning.
With that said, we have just announced the launch of a new Custom Field type → People 
We believe this field will help to resolve a lot of the pain points users are experiencing in this thread.
You can check out all the details of this new People Custom Field on the post below 
We’re looking forward to hearing your feedback and how you will use this new custom field in the comments over on the main post!