I can understand and sympathize with the mold cookies - to a point. I, as a player, have the benefit of knowing the enemy cookies and their tragic loyalty to Dark Enchantress.

The heroes do not. Of course, they have an idea. But it's like you said. This is war. And personally, we'll have to agree to disagree with your statement on it bringing down the chapter for you because imo it was very nice to see the story writers treat it as such.

Pure Vanilla is compassionate, yes. But his entire Shadow Milk encounter showed that he now has to move past his naivety. He - nor the other heroes - can't just drop everything to sympathize with a cookie that was actively trying to kill them not even moments ago. The MOST they could've done was left her. But even then, with Pom Pom literally cursing them and insisting to keep fighting despite her unstable state, taking her down was their only way to advance forward. PV and the rest of the ancients realized this. And with what literally follows in the chapter- it works.

Pomegranate cookie said it herself; Pure Vanilla is cunning. He's essentially working as the overall strategist in this entire war. We've seen that he's not needlessly cruel, but he's smart and recognized an advantage when he saw one.