The issue with the reserves not being at hand had to do with limited space in the barracks, as the city's facilities were simply not equipped to house tens of thousands of soldiers.
To compensate for this, many make-shift buildings had to be created, and given the urgency of the situation they had not been able to be properly heated and furnished yet.
So in this cold weather, most of the soldiers were allowed to stay the night at their homes.
And this lax in military discipline had become especially egregious these past days as Perseus had decreased the intensity of these attacks.
It seemed his strategy of lulling the enemy to complacency had worked.
Cambyses would come to know about all this later, but for now, she decided to go by Juminus's suggestion.
Now, the idea of pulling back the active defenders from atop the walls to bolster the defense of the manor certainly had its risks, as anyone could guess.