This is critical when developing complex lead funnels from non hubspot, or non-hubspot-integratable platforms. For our purposes, an inbound lead needs to be assigned to an owner and that owner will be in a team. There will be many teams and each team must recieve only certain leads. For the API to be usefull it would have to have the following basic methods:
Get Team Members by Team ID
Get Team ID by User ID/Email
Get Contacts by Owner/User ID
Get Owner/User by Contact ID