In Lux's eyes, Jarvan IV's direct and hasty attempt to absorb the Northern Wanderers under her command was a little too rash.
Even if he didn't know she harbored rebellious intentions, the Noble Exemplar ought to have known better than those fools.
Trying to annex her private army in such a rush was a little too dismissive of the Noble Exemplar.
Had she been away from Demacia City for so long that Jarvan IV had already forgotten how she'd earned the title of Noble Exemplar?
But by Jarvan IV's own reasoning, his choice was perfectly reasonable and well-founded. The reason was simple: as far as he knew, there was no one named Yin Nuo in Freljord.
As far as Demacia City was concerned, one of the three northern power players had always remained hidden. So, in Jarvan IV's view, if he asked Freljord's private army to join the campaign, then unless Luxanna went herself, the only one who could command it was Sona.
Hadn't Sona represented Freljord at the Battle of Tobicia?
Back then, she hadn't held any real power, yet she'd still paid close attention to the course of the battle. Though Freljord was now very different from what it had been, Lux still had only a limited number of people she could rely on.
Jarvan IV had made a point of looking into the Battle of Silvermine City. Lux had certainly gone to Silvermine City herself because she was anxious to rescue her brother, but many of her subsequent actions suggested that she had no commander under her who could take charge of the whole operation.
So unless Lux went in person, Sona was the only one who could lead troops south.
Jarvan IV had little confidence that he could fully absorb Freljord's private army if someone else