You could say the same for rulers having an estate in a region of some lowly knight. And yet it won't happen, because there are also game-mechanics that equal "obeying". For example, combat settings. The marshal does tell the ruler where on the battlefield to stand.
Err, what???
It doesn't get much more subjugated than being subject to military commands by someone.
He can always, you know, not be in any army.
Except no one actually sees Rulers as subject to Marshals, whereas Rulers as Knights
were seen as subject to their lords. Yeah, the Marshal says where to stand...But the Ruler can remove himself from the army whenever he wants, too. Cutting Rulers off from armies unless they are the Marshal is going to be a major problem. Ruling is a time-consuming enough job, Marshaling on top of that would be painful, and not being in an army removes you from a lot of the battle interactions.
