I'd say if they roleplay reluctance, you could spare them the Shadow point -- or at least not hit them with Shadow for every repeat instance of the same deed. If they do it with bloodthirsty glee, then penalise away until their level of Shadow and Flaws matches their roleplayed attitude.
In a narrative-oriented game, other fleeing adversaries are beaten. They are not going to change their mind the minute they get behind the nearest tree and start risking their lives for the chance to inflict one more small piece of attrition on a Company that has thoroughly bested them. They are going to throw down their weapons (being aware on some level that being unarmed makes killing them a worse misdeed than otherwise?
) and head for the hills, not look back, and not influence the ongoing progress of the plot in any way that will disadvantage the Player-heroes.The habit of leaving no foe alive is probably deep-rooted in many gamers (like BobusX's group) , raised on a diet of needing the kill to achieve the XP, and perhaps from a history of playing under competitive GMs who made them suffer any time they've adopted a heroic attitude and not tracked down and slain every survivor.
In the best adventures, the Player-heroes should be under other pressures that mean they cannot afford the time and possibly the splitting up required to run down multiple escapers. Pursuing their goal should be more urgent and more important than pursuing the survivors.
Cheers,
--Os.
