they are all basically near-zero probability to be used.
based on the rest of the game the the fleet choice at the end of the war is "global stats bonus" (supplly), "event stats bonus" (keep order) and "something you can use later" ("reserve")
the first two are already given result, the keep in reserve perhaps no [very slim probability].
most of the switches in the game had only functional or cosmetic effect, "fleet: supplies" is used for spwan a couple of npc and change a couple of dialogues in the aftermath and in the open world segment after the war.
i don't know if you were around during the synod release, and the absolutely belief many have the switch "annah support" was needed for future event. when is obviously just set to change annah reply to bertricia two dialogue box later.
and in fact in return of stineford the switch is never checked.
Slim probability>no probability.
As the game's most ardent supporter of the painfully outdated "Early Monument" plan, you should believe in that more than anyone.
The difference between Arclent Acceptance and IW_Nyst is the fact that we are
still getting the former stat from finishing quests in content added after the IW, so obviously it's likely to be used again. IW_Nyst? Not so much.
And yeah, I don't believe any of the Fleet switches will see use again either, to be honest. But Reserve DID already serve a purpose in the IW.
Supplies= Additional AA but no IW bonus
Reserve= Neutral AA but small IW bonus
Order= Negative AA score but major IW bonus
You'd honestly say that keeping the airships in reserve is more likely to be a positive in stat-checks, than delivering supplies, in a game that rewards altruism as much as this one? You only keep that reserve during the war. After the aftermath you have the same fleet around with no losses and only the reputation gained from what you did with it. Seems like you'd be remembered more fondly in any given side-quest's stat-checks, if you went out of your way to help the entire continent.
But whatever. The fleet part is admitedly pretty ambigous. The importance of IW_Nyst vs Arclent Acceptance seems far more clearcut. Seems decently possible for Sierra to hide a Shining Sword or some less obvious "thumbs up" for the player near the endgame, behind a skyhigh Arclent Acceptance requirement, and most of us have taken conciderable hits to this score after Neranda and potentionally also Elleani's events.
But you know what? Screw all of that. Because the reason I made my original comment was to say that optimization is tricky in the most recent updates, and that no newbies should take the advice of you or me or Thosha or anyone as fact. I don't know, you don't know, no one knows. So let's all stop pretending to have all the answers, hmm?