In my view there is no rule of thumb as it ‘depends’. It depends on how much time you want to allocate to a team leader for such activity and what you want them to handle / manage.
Firstly I think it comes down to a good scorecard that the team leader is using and cascades to the team member. That should avoid micro managing and just checking in on the scores.
Then consider other activities that you want the team leader to undertake. For example, time supporting, training, coaching, listening, reporting……
If you are using contractors then there should be savings on not having to do reviews, appraisals etc.
So I’d say work on those factors.
1. What you want them to “handle” and how long that will take per team member per day / week
2. Then considering your desired ROI measure for the team leader then how many hours per day / week can they commit to this.
3. Two (number of hours they have available for managing) divided by one (number of hours required to manage one) should give good indication.
