Okay so we come back to the changing facing rule that says verbatim: "changing facing in this way does not count as moving,
"
When a Standing fighter is activated, they may turn to face any direction their controlling player wishes, before making either of their actions. Changing facing in this way does not count as moving,"
Which yes, is very much back to, since this was pointed out back on page one of this discussion.
It really is not as cut-and-dried as you are hoping to be the answer.
When Activated, a fighter can get a free change of facing, which does not count as movement. When Activated, a fighter with the Group Actication (X) special rule can also trigger that special rule. When Activated, a fighter can perform up to two actions (or one Double action). How to Activate a fighter is explained on page 101 of the N'23 core book. Activating a fighter giving a free change of facing that isn't movement is explained on page 102 of the same book. In the section about Activating a fighter and then taking Actions.
CHANGING FACING
Fighters can change their facing during their Activation, representing them turning in place, or turning their head from side to side. When a Standing fighter is activated, they may turn to face any direction their controlling player wishes, before making either of their actions. Changing facing in this way does not count as moving, and therefore can be combined with any other action.
That's the wording at the crux of this question that started the whole thing, and also of the question currently under discussion.
When Activated, at the start of the Activation, before taking (any sort of, even firing an Unwieldly weapon) Action.
So for the first question, it turns out that it can be combined with Simple Actions, but should be done before either Action, so turning between Fast Shot shots doesn't seem to fit. Nor for things like Gunslinger where you are shooting twice during one Action.
For things like Overwatch, the fighter is not being Activated, but are just getting an Action, outside of their own Activation and during someone else's Activation. So things that trigger off being Activated - like Group Activation, like the free Change of Facing, like several Tactics Cards, don't trigger. No Activation, no trigger.
Overseer complicates things, and isn't "a failed argument," or "obvious," or "people just being a c**t," as we have seen. It is a poorly worded rule. IF it gives a full extra Activation inside the Overseer's Activation, then it stacks those triggers. Both the Overseer and the target get free change of facing, get to use Group Activations, get to trigger Tactics Cards, etc. IF it gives two Actions but not an additional Activation, then it does not trigger Group Activation, does not trigger various Tactics cards, but also does not give a free Change of Facing. That's "as written."
Is that what is "as intended"?
No one knows, because the several writers involved have not said, despite it being a frequently asked question for half a decade now. That's the point. Even if we double back and repeat the bits we have already discussed.
how do you see the turn working with overseer?
Despite my being rather in the middle, and arguing that it is a matter of Arbitrator interpreting a messy rule, I will try to walk through the steps that would result:
Leader uses Overseer, and targets a Champion:
1. Activate Leader.
1a. Leader, Activating, chooses whether to use Group Activation (2) on fighters close to the Leader, and chooses the order of Activation.
1b. Leader, Activating, automatically triggers Group Activation (Exotic Beast), and chooses order of Activation.
1c. Leader, Activating, gets a free Change of Facing if desired, before either of its Actions.
1d. Leader, Activating, triggers any Tactics Cards which trigger when a friendly fighter is Activated, and they may be played on the Leader.
2. When it is the Leader's turn during the Group Activation chain, the Leader uses Overseer (Double), targeting a Champion (potentially one of the fighters who had been part of the Group Activation, for that matter!)
2a. The target Champion does not get a free change of facing, since it isn't them Activating, but rather the Leader's Activation during which they are Acting. [*Note that the target can end up changing their facing through actions such as Move (Simple), or Charge (Double), or Take Cover (Basic), or Stand Up (Simple), or Crawl Through Ductway (Double), etc, all of which allow a choice of facing as part of that action]
2b. The target Champion does not get to use Group Activation (1) on fighters close to them, since it isn't them Activating, but rather the Leader's Activation during which they are Acting.
2c. The target Champion does not trigger Group Activation (Exotic Beast), since it isn't them Activating, but rather the Leader's Activation during which they are Acting.
2d. Tactics cards that trigger on Activating a friendly fighter may not be played on the target Champion, since it isn't them Activating, but rather the Leader's Activation during which they are Acting.
2e. The target Champion performs up to two Actions, as appropriate to their current status (Standing, Engaged, etc etc).
2f. The Leader's Activation ends. If there are other fighters in the Group Activation chain of the Leader's Activation remaining, Activate them in turn as appropriate.
That... that looks to be how that would work if Overseer does NOT give a full extra Activation to the target within the user's Activation.
Does that seem about right?
Alternatively, if Overseer DOES give an actual Activation-not-needing-a-Ready-Marker-during-the-user's-Activation, it looks like this:
Leader uses Overseer, and targets a Champion:
1. Activate Leader.
1a. Leader, Activating, chooses whether to use Group Activation (2) on fighters close to the Leader, and chooses the order of Activation.
1b. Leader, Activating, automatically triggers Group Activation (Exotic Beast), and chooses order of Activation.
1c. Leader, Activating, gets a free Change of Facing if desired, before either of its Actions.
1d. Leader, Activating, triggers any Tactics Cards which trigger when a friendly fighter is Activated, and they may be played on the Leader.
2. When it is the Leader's turn during the Group Activation chain, the Leader uses Overseer (Double), targeting a Champion (potentially one of the fighters who had been part of the Group Activation, for that matter!)
2a. The target Champion gets a free change of facing, because they are Activating.
2b. The target Champion may use Group Activation (1) on fighters close to them, since they are Activating and as part of Overseer, not as part of a Group Activation.
2c. The target Champion triggers Group Activation (Exotic Beast), since they are Activating.
2d. Tactics cards that trigger when a freindly fighter is Activated may be played on the target Champion, because they are Activating.
2e. The target Champion performs up to two Actions, as appropriate to their current status (Standing, Engaged, etc etc).
2f. The target Champion's Activation ends. If there are other fighters in the Group Activation chain of the target Champion's Activation remaining, Activate them in turn as appropriate.
2g. The Leader's Activation ends. If there are other fighters in the Group Activation chain of the Leader's Activation remaining, Activate them in turn as appropriate.