And trying to evac vehicles which themselves aren't rated for space-combat in unarmed transports, in front of said 3 supercarriers...
-Heck, even after the factories were gutted, tanks still rolled out of Stalingrad and Lenningrad still upgraded and repaired tanks.

The Covvies also had this bad habit of mistakening Human tech for forunner artifacts.
-Which is entirely why Cleveland, Ohio was never glassed. As the Colenel would say, [url=http://halo.wikia.com/wiki/Ruwan_Ackerson]"You're welcome."[/url]