I have the vague hunch that this is going to hurt someone.
Lest we forget, Lizzie is the center of the Flow hivemind, and she gets direct telepathic feedback from each and every individual in it. You can imagine having a multitude of soldiers hacking away at her children is a tad unpleasant and liable indeed to make her, literally, lash out.

If the troops on the other side of the barricade are lucky, they’ll just get ripped apart by those Tsochari. If they’re less lucky, they’ll be parasitically burrowed into and then ripped apart. If they’re very unlucky indeed, Lizzie will have the Tsochari actually occupy their bodies completely and force them very painfully into obedience to the Flow.

Suffice it to say, storming the main palace building just got crossed off the list of options.