The gods watched as they saw the final preparations being finalized, they made their bets on who would get to see Valhalla but they also knew that not every warrior with a sword would see the great halls of Odin, the gods were anxious about the valkyries waiting on the souls of who may fall in battle.
Signy carried out the assignment of his father but that was his first time taking a life despite a war looming. King Asmund thought this was the best way to pop his son's cherry as he needed to get that first kill off his chest and there was no better way to do this than with the life of a man that would draw out the conscience of Signy.
Vestfold had assembled their forces with King Asmund's position where the first battle would inevitably occur, they had the advantage of preparations and King Asmund was going to use this time to its fullest effect.
Creation is hard, cheer me up!