We’ve used Teammate groups mostly for access and notifying rules at the moment. I’ve grouped them by department, and then if there’s a sub-group within that department (managers, account reps, those responsible for “highvalue” shipments, etc.) to use in rules. I’ve avoided using named teammates in rules and rather using a teammate group, even if right now it only has one person in it, to future proof for later. 

Hope that helps!