How wrong am I to think that they generate irregular orders during their loss of lieutenant turn, and if they choose to spend one they meet a cancellation condition?
A Fireteam breaks if you spend a non-Regular Order on the Fireteam Leader. How to keep a Fireteam together in Loss of Lieutenant? Don't spend non-Regular Orders on it. How to achieve that? Don't activate the Fireteam while in LoL, or have some Regular Orders generated by your troops with Veteran skill (their Orders stay Regular in LoL) or burn through your Command Tokens to turn your Irregular Orders into Regular Orders. ...preferably, of course, don't get caught in LoL in the first place. But it is sometimes easier said than done ;)
Tactical Awareness orders are not effected by LoL also so you can spend those to activate the Fireteam as long as the trooper with TA is the leader. O-12 Prestige is also available in ITS15 is you have no TA which creates a Regular order at the cost of a Command Token which is slightly better deal that converting an Irregular.
As said above fireteam does not break and will not break as long as you do not spend irregular orders to them, it is another thing to consider when using fireteams.
