Once the war mobilization order is issued, all knights with titles must unconditionally obey the dispatch from Red Castle and go to the battlefield.
To gain something is to lose something, a truth unchanged through the ages.
A title is a knight's highest pursuit; with it comes wealth, status, power, and everything else. But at the same time, a title is also a knight's greatest bind, for one must exert all efforts to maintain one's wealth, status, and power and uphold the system.
When the Shadowflame Grand Duchy is in distress, it is the unshirkable duty of all nobles.
Russell did not complain about anyone. He would not complain about Grand Duke Kunstan, who issued the war mobilization order, nor would he complain about Baron Roman, who conscripted him to the battlefield, because he had received too many benefits from the Shadowflame Grand Duchy, from Glowing Valley.
Of course.
The more important reason was that he had already prepared a way out for himself.