Yes, and those who approve timesheets, like managers, don't do anything in Workfront other than looking at reports. There is no need to require them to have planning permissions just to approve timesheets.
In our company the project managers "approve" timesheets. This means in Workfront> they show up as that person's manager - because we can't rename that fields to "Timesheet approver" and it also completely makes the "Org Chart" view under a user irrelevant, because it builds the org chart based on the "manager".
There should be an ability to control this (timesheet approver NOT being the manager)
There should also be an ability to hide the org chart visbility when it's completely wrong, but there isn't.