Is it possible to utilize different credentials (User/Group) for ExecStartPre and ExecStart?

The reason being is that I have an update/synchronization job that needs to happen when the service is not running and it seems like a perfect time to initiate the update just prior to whenever it starts regardless if it is on a set schedule or a restart after a failure or manually starting the service.

The credentials used to run the service is extremely minimal but the backup job needs extra rights to the backup location...which I do NOT want the running account to have.

Or am I just being dumb and should schedule another job that periodically stops the service, runs the backup and starts the service up and leave it at that?

LHammonds