I think that it is clear (based on Mercenary Copilot and Recon Specialist) that Inspiring Recruits ability stacks, hence if you have a Decimator with 3 copies of that card, you may remove 4 stress tokens from a friendly ship in range 1-2.

More interesting question is if you are allowed to use this once per turn (as all cards share the same name, hence this is considered to be the same ability) or is it once per turn per card (Gonk comes to my mind). Other cards were not limited to be used once, hence two merc copilots with Gunner might be triggered twice. Recon refers to action which is performed once a turn.. Gonk is listing two actions, but then you have 3 cards...

My bet is on the first one but I cannot find any ruling to clearly resolve this.

Many thanks for your attention and support.

Recruit is once per round, so it's... once per recruit per round. You choose when, if you could trigger multiple.

Same thing as Merc Copilot. You can trigger it multiple times in the same opportunity, or opt out of some of it.

Not really sure what benefit you'd get from stacking recruits though. Even if raging nothing is going to have more than 2 stress that wants to get rid of it. If in the unlikelyhood you face a stresser and youre raging, ok yeah then it would be useful but thats also a LOT of investment to counter an unlikely opponent.

So, how do you differentiate which card has been used and which not? Game mechanics have never seen something like that before (both Recon and Mercenary are triggering altogether at the same time).

FAQ:

Q: Can a ship perform the same Upgrade card action or Damage card action more than once per round?

A: No. Having more than one copy of the same card that requires an action to trigger its ability does not allow you to perform that action more than once per round.

Q: If a ship has more than one copy of the same card that does not require an action to trigger its ability, can it trigger all of those card abilities?

A: Yes. For example, when a ship equipped with two Mercenary Copilots is attacking, it can change two results to two results

I see your logic, but I am not convinced... especially due to the first "Q" quoted above. Although neither is the right answer for my question... :/

So, how do you differentiate which card has been used and which not? Game mechanics have never seen something like that before (both Recon and Mercenary are triggering altogether at the same time).

FAQ:

Q: Can a ship perform the same Upgrade card action or Damage card action more than once per round?

A: No. Having more than one copy of the same card that requires an action to trigger its ability does not allow you to perform that action more than once per round.

Q: If a ship has more than one copy of the same card that does not require an action to trigger its ability, can it trigger all of those card abilities?

A: Yes. For example, when a ship equipped with two Mercenary Copilots is attacking, it can change two results to two results

I see your logic, but I am not convinced... especially due to the first "Q" quoted above. Although neither is the right answer for my question... :/

Recruit isn't an action, so it's irrelevant.

How you define which one you've used is also not relevant. You can turn them sideways or stick a token on them or something.

You can use multiple, and you can choose to trigger one not the other because the triggers are voluntary and independent.

That's RAW, right there on the card.

Keeping track of them is on you. Turning sideways is a good idea since thats a mechanic that isnt used in xwing, or put an otherwise unused token on it (energy, mission stuff, crit).

Its not an action so it falls under the 2nd FAQ quoted.

Tracking multiple Inspiring Recruits would be no different from just tracking if the one you have has been used or not. When the trigger happens you have the choice of using it or not; with multiple copies it means you have the option of using more than one.

What could make Inspiring Recruits tricky is simply that there are more opportunities for triggers to happen which can make it harder to track things in your head. With Recon Specialist you're only getting to take the Focus Action once per turn to trigger all the copies you may have. With Merc Specialist they trigger anytime you make an attack so all always work but few ships are going to worry about making multiple attacks at different times as well. Your ship with 3 Inspiring Recruits sees triggers every time a ship in range loses a Stress so it could see 4 stress removed from one ship or 2 stress removed from 3 ships.

What about timing? Can you have 2 Stress, receive a 3rd and then remove all 3 in one go using 2 Recruits? I.e. can you trigger the 2nd recruit off the extra stress removed by the first? Or do you have to remove 2 stress, and then remove another 2 stress?

It makes absolutely no difference. Using n inspiring recruits whenever you clear a stress you clear up to n additional stress.