No I mean it seems like nobody gets the plan.

I call it Plan: Diplomacy.

There is absolutely no way we can survive a direct confrontation with the Royal Army at full force as we are. If we treat the spies with hostility, King has permission to wreck our shit. If he learns I've hired mercenaries, he has permission to wreck our shit. If the spies don't come back, he has permission to wreck our shit.
The only way to keep the spies from going "Hey Isolde is plotting something" is by treating them as allies. We invite them in, put on our best clothes, and behave well while I explain that these are not in fact mercenaries, but a few extra bodyguards to fend off the local bandits, as they've gotten rather rowdy as of late.