Sure, as a group, jarheads, you bet! Grunts are infantrymen, though. They can take choppers or tracks or trucks to get to the fight, but the number one means of transport is a couple of legs. To be fair, the army does have a few of these dudes.
Heh, I got legs too, but mine are just for walking from one vehicle to the other, making sure they get where they're going. 88N In the US Army.