Tactical Awareness clarification

Hi! The way the rule about changing the leader of a fireteam is written leads me to think that, in order to use the irregular order provided by Tactical Awareness to activate the fireteam, the trooper with TA must already be the leader of the team (either because I designated it as the leader during the deployment phase or because I activated the link with a regular order and designated it as the leader).

Is this correct? Or is it possible for me to activate the fireteam, which was led by someone else, and assign the TA troop as leader while using the TAs irregular order?