Dynamic group updater scheduled task - multiple admin services

Hello,

I'm currently optimizing dynamic groups processing after upgrade to 8.2.1 SP6 and I've distributed our dynamic groups evenly among three administrative services running on servers A, B and C. 

The nightly Dynamic Group Updater scheduled task has "Execute on:" set to server A but I think that this performs the rebuild only for groups that are assigned only to server A. I'm looking to find a way to set daily rebuilds of groups assigned to servers B and C. 

Can I somehow duplicate this built-in scheduled task and assign one copy to server B and one to C? In some documentation I also saw that the "Execute on:" should have a choice for "all servers", but in the dropdown I can only choose one of the three.