According to the satellite feed, the retreating mecha simply kept going, all the way to the capital.
By mid afternoon, they still hadn't seen any threats close enough to engage, and Max began to wonder what was going on. It wasn't clear if the front line battles had stretched their resources too thin to bother with objectives like the one they were on or if the enemy was regrouping.
Sunset brought the answer. A reinforced mecha wing with two companies of infantry and a bomber squadron. Textbook rookie Commander tactics.
Twice the numbers that the defenders can count on, with a fully mechanized final assault, led by expendable infantry. The exact reason that Max's veteran neighbor Dave hated everything to do with Kepler Military Commanders.