Rainbow Mages and Searching in the Early Game

[Valerius]

To protect against opportunistic remote attacks like seeking arrow use decoy commanders and/or forge magic gear.

Choose a stealthy rainbow mage so that by the time your pretender appears in a scouting report he's already sneaking out to search the next province.

Research Thaum. 1 ASAP and, assuming your pretender has S2, script Returning to escape battles and assassination attempts.