Currently, users are all individuals. In the workflow (see attached image), when I want a lead assigned to someone from the sales team, I need to manually list every person in the sales team in the workflow. If the sales team are part of several workflows, this is a lot of work with a risk of error.

Creating a team of users, with the option of a user to live in multiple teams, means the workflow could select SALES TEAM, instead of each individual in the team. This means, when the members of the sales team change, only the SALES TEAM bucket needs its contents updating, instead of going into every workflow where members of the sales team are selected and making changes one-by-one, with an increased chance of errors.