For Zion, even if he couldn't immediately identify who was trying to infiltrate his territory, it didn't really matter. The repeated rogue attacks—where wave after wave of warriors were sent only to be slaughtered—meant that the enemy had already sacrificed too much to walk away now.
They were fully committed, and that left them with only two possible outcomes: be annihilated by Zion once he uncovered their identity, or crumble from within as their forces were gradually depleted, leaving them as nothing more than a fragile house of cards.
And if, in a desperate attempt to escape destruction, they chose to go down in flames and leak the secret to every faction across the land, that too would be a foolish move. Not only would they incur Zion's wrath, but they'd also risk enraging the monarch of this domain. Doing so would guarantee their total eradication.
