A Grave Robber And an Exile Walk Into a Bar
Actually, "The Grave Robber and The Exile" is not too long. Just don't plug any subtitles onto it. It comes off a little edgy to me because both labels are negatively charged. They are factual descriptions but could be taken as insults. Maybe a little bit edgy is the tone for which you are going.
Is the king hiring these guys because he wants some dirty work done with plausible deniability like a medieval black ops squad -- or do these protagonists have some unique skills or talents which make them the only candidates for specific quests like Sir Gawain and the Green Knight?
If either uses a signature weapon, you could copy the name of that like the manga series Claymore.
Other options:
For King and Country
His Majesty's Beckon
Medieval Black Operations
Clandestine Quests
Skullduggery
Two White Dudes with Swords