The Battle of Bentheim stretched on for hours, then days. The sandman monoliths kept advancing to the critical planet which the aliens seemed hellbent on reaching!
Over the course of the battle, the Mech Corps, the Starfighter Corps and the myriad of domestic and foreign outfights learned one brutal lesson.
They were wholly outmatched.
The sandmen previously posed a considerable challenge to these forces. The general consensus that humans settled on was that the sandmen were individually weak, but extremely numerous and very willing to go all out to achieve their objectives!
Against weak and numerous enemies, the Bright Republic thought it was enough to bring numbers of their own in order to reduce the quantity disparity. For this reason, the government didn't hesitate to station over half of the entire Mech Corps and Starfighter Corps in the Bentheim System!
The military should have brought more mech divisions and starfighter divisions.