Several sites on my dashboard - need to maintain different email addresses

Site URL: https://glasscityimprov.com/

I edit 3 sites on my dashboard, they seem to be connected to one email address, I need to separate them out to different emails as they are "owned" by different orgs/entities. 

For example, what happens if I no longer can edit 1 of the sites, but will still be editing the remaining 2 sites, can't I just hand that single site over to someone else and have them log in with their email? 

Thank you