My usual practice in circumstances like yours is to ...
- Create a checkbox field for the to-be-deleted records. It would be a formula-checkbox, in your case, where the formula evaluates to true if Nz([Related Team Member],0)=0. That formula works whether or not Related Team Member is set to treat nulls as 0 in formulas. Sometimes, I use a plain checkbox, not a formula checkbox, to designate the to-be-deleted records. In particular, I use a plain checkbox when a user who lack permission to delete wants an automation or an admin to do so.
- Create a report that lists all the records on which the to-be-deleted checkbox is checked. This enables you to see what's happening, and to delete a batch if the automation is not working.
- In the automation, use the to-be-deleted checkbox to filter the records that the automation should delete. If you don't expect more than 1000 deletions per day, it may be desirable to use a scheduled deletion. Alternatively, you could trigger the automation whenever a record is modified and the to-be-deleted checkbox is checked. However, beware that if more than a 1000 records get modified as to-be-deleted at once, e.g., by a mass import or by some other automation, then you may hit the 1000 limit, even though your automation triggers on one record at a time.
- Thus, if needed, you may have to devise several automations, each of which uses, say, modular arithmetic on Record ID# to guarantee that at most 1000 of the deletable records will in fact be deleted by any one automation in the group.
