Muster puts warbands on your board. Currently the Lush Coast is ruled by bandits, and a campaign would be required to place your warbands there.
This probably affects your choice to move to the plains too, maybe even the play of warning signals, so feel free to craft a new turn.
Remember you can play cards face down to advisers, if you do just message me the card to place, or say “furthest card left in the search draw” or whatever.
You didn’t specify, but I’ll point out this means the vision is discarded to the Provinces.