C
They probably should have done this to start off with.
Duchy was shorter ways to their lands
You direct them to your senior, King Tinwulf, because only he can give them troops if he feels like it.
The diplomats murmur between each other, then thank you collectively and leave in a hurry.
959 AD, Winter
Your wife has given birth to a boy! His name is 'Salus', and he will succeed you as
Estwalf II, unless you screw up like your predecessor did.
959 AD, Midwinter
Loads of refined, polished copper and malachite crafts arrive at your Treasury, dink dink dink!
You receive news that your senior, King Tinwulf II, has declared that the matter of holy war of Eist against southern kingdoms is not going to be an affair of Dahnia or Tven or Hel peoples.
Few days later, you receive a report of sightining of lizardmen! They have appeared at the base of the mountains where the funky Rainbow Lizards dwell. Their hissing, guttural language is totally alien, and the savage humanoids have a penchant for destruction and human meat, as your outlying settlements had learned first-hand.
A) A plague of lizardmen out of nowhere? We should call upon a Wizard because it's clearly the work of supernaturals!
B) Maybe we should send money and trinkets to the lizards to placate them?
C) Ah yes, our Army would use some target practice. To arms!