Blue could mean Navy or Air Force, but usually they became the Enemy. In a pinch, which was most of the time, they enemy had Green vehicles, too. The power of Jeeps increased after the series Rat Patrol made its debut, and then a Jeep with a machine gun could knock out a half track or open self-propelled gun. You could mount a machine gun, mortar or bazooka on a Jeep. You could tow a cannon with a jeep, but not mount a cannon on it.
Half Tracks can even mount a cannon.
The second best vehicle on the battlefield. Tanks can go anywhere, knock down any building, run over any other vehicle except another tank or a train. To blow up a tank, you need another tank, a big cannon or a bazooka. They could be knocked out with machine guns or cannons. They could be knocked out by machine guns and cannons.