You seem to be deliberately ignoring the fact that there's a lot more than time involved here.
So are you saying that any secession during wartime that doesn't immediately declare war on its parent realm is a strategic secession?
So you agree that Enweil has more or less lost the war already, too. If you are attempting to argue that if Riombara had kept Iato, Enweil could have won the war, but now they can't, you're not doing a very good job of it.
Win the war, no, but that doesn't mean that Enweil can't try to reclaim Iato anyways and try to drag out the conflict as much as possible. War isn't just about winning. Just because a realm is dommed anyway doesn't mean it's fine to cheat against it.
Please describe for me exactly how this realm with one depopulated region and one noble will cause a measurable unfair disadvantage for Enweil.
Again, just because the war is so lopsided doesn't mean that it's fine to cheat.
I've already given reasons why this hurts Enweil, though you seem to intentionally ignore them. I even repeated them. Seceding grants an instant passive defensive bonus to Iato, and grants the potential for increased offensive capacities.
So what if it has little infrastructure now? Does it really make it any less of a strategic secession if the guy waits until after the verdict is made to build a ton of it? Again, you put time in question. "At the time of the secession, the military power of the colony was small" appears to be your argument here. That one depopulated region can expand, you know? It can build infrastructure. Nobles can join it. Who knows how strong it will be in a month? The gains need not be immediate (though I will stress again that there ARE immediate gains) to be strategic. Enweil hopes to impose as much attrition as possible to an enemy it cannot defeat. This secession allows Riombara to cut down on a whole lot of attrition by having a place right by Enweilian lands for its supporters to attack and expand from. Or are you going to tell me that the distance from the capital penalty between Pahk and Iato will be the same as those Iato had from Riombara's capital...?
