Border towers manned with observation and Ping casters to detect and eject enemy scouts.
Florin tells Carl over Warlord Chat what the towers being raised along the borders are actually for: full coverage against enemy incursions. The recipe is a tower manned by a group of four or five people carrying proper observation and Ping spells, which keeps enemy scouts away by spotting them and triggering their forced teleport home.
The system already works — the towers have bounced a The Dream scout and one of The Prism Kingdom's octopus-faced operatives. Florin insists on getting more up fast, betting his left sack the Princess Posse is already infested with enemy spies and calling for an immediate full sweep of their own territory.
Watchtowers raised along the faction borders, each staffed by a small group of spellcasters.
The Princess Posse's counter-intelligence backbone during the pre-war scouting phase.