Make up your mind. Either hierarchy is incredibly important in a medieval kingdom, or it isn't and following it is "a spat over authority". Or maybe you catch on what actually happened in actual kingdoms instead of the idealized notions you spouted before; not everyone agreed on everything and hierarchies and loyalties both were quite often not as clear-cut as on paper leading to much disunity.
In any case, given that right afterwards Terenas listened to Uther when it came to recalling Arthas's army from Northrend (and that this time Uther was very much right that going there was a stupid initiative), it seems your idea of what should happen and what actually happened conflict once more.