What do you mean?
The hobgoblin army was not from another continent it was from a neighbouring region and their attack wasn't random since Redcloak (and their troops had beef specifically with Azure City). Also without Miko Shoo would have killed Redcloak and Xykon here and there, and while thet would not have won the battle by itself it would have saved the Gate. Haley then could have met with the fleet and and a counterattack could have been organized without having to worry about Team Evil.
So? The point remains that if he hadn't focused on family only his Gate would have stood (or at least had a better chance to). Freak accidents happens and Girard should have been better prepared.
EDIT: his gate was literally the only one would could have fallen this way, if the OotScribble had joined forces then their Gates would have withstood what fell them.