They, however, share the same action lag. As for tells, both heads are separate players. Let's say we have a Boerlk and Misfara the ettin. Let's say that Boerlk want's to join the Fortress while Misfara wants to be an Outlander. So you two go in, defend Fort against an Imperial raid at the watcher. After fending off the raid, you bash down the dwarf marshall for the good measure. Boerlk apologises the marshall profusely afterwards (the Marshall might die, or Boerlk manages to flee and quaff). While defending the tree, Boerlk makes his best to attack nightreavers on sight.