((Ghazkull, I specifically said I'd leave most of the reserve behind... Either you retcon, or I'll assume Malcador is lying.
Also, some fun math. You stated I got 1 million men. Let's assume it's an overstatement and I got 500.000. Let's also assume they each eat 1.5 kg of food a day, and let's say I got 1 month worth of food. 30*1.5*500.000/1000=22.500 tons of food. That's right, someone managed to steal over TWENTY THOUSANDS TONS of food (So a stack 50 meters long by 50 meter wide by 9 meter high) without Azthor's spy, or anyone else, noticing. Yup, we got a badass over there. That, or the GM didn't think it through before creating this story arc. :p
Also, I assume I do not yet know of Aeverys' return. I'll get the message in a few days I guess.))
Whole regiments seling their weapons? There is no discipline in this army anymore. Time to move.
Plunder the local countryside for food.
Investigate the weapon sale. Who did they trade with? Also, question the guards that let food for a million man be stolen.
Appoint one of my trusted lieutenant as Head of Logistic.
Appoint the House Guards to guard the food.
Probe the defense with half a dozen regiment of militias on a small section of the perimeter. Send the regiment that sold their guns as well, they might as well learn it was not a good idea.
Oh, and inquire into the theft of my Guard's vehicles and the orginin of the irregulars' flamethrower.