I understand that, but this is the only development in the story that feels artificial or manufactured. Of the two options on the table, overthrow an immensely powerful and corrupt monarch or escape and avoid capture, which sounds easier? It just doesn't seem like this danger has any immediate threat. They're chasing Eren and Historia, if they aren't there to be captured nothing happens.
It doesn't take an Armin to figure they're taking the hard road for whatever reason. To me it seems like this is too personal for Erwin and no one is questioning his decision making. Maybe that's the point? But Eren is being a tool (nothing new) but for once it's not in line with his original goals.