I second what @Pagenoi wrote:
As an Enterprise client, this is one of the most limiting and frustrating missed opportunities in HubSpot. The fact that you only have the four options (Everything, Team only, Owned only, and None) is incredibly frustrating and then you can only add someone to 5 teams makes it practically unusable by our Business Development teams. If I have a BDM who works in 7 markets and another who only works in 3 and they are on a team together then the person who only needs 3 will see everything from the BDM who has 7! That’s ridiculous.
We too would be happy to explain the use cases that would make this reasonable for HubSpot and would allow us to use the system more accurately.