The rulebook says: "When using the "Character Result" on the Action Dice to move and divide an army that leaves a region, it must contain at least one Leader or a Companion".
But right in the next line it says: "The Companions are not obligated to move with the army, because they can stay in a territory alone".
Ok, correct me if I'm wrong. For instance, if I have an army that Strider leads, then I get a "Character" result on the action dice I decide to move Strider's army using this dice, but I chose to move only the army, making Strider stay.
So, this is a legal move? I assume yes, because Strider give then a command (so, according to this theory, Saruman could do so too, right?). But it may be no, because he is not going with then.