I suppose that Ground Forces personnel would have some sort of mobile fire support platform to help them out planetside, you can't always assume that you'll have air and space superiority. So some sort of Phaser Tank, like a "Hammer's Slammers" type tank, with a 2 or 3 being crew, would be made. It would have shields, armor, phaser arrars or a phaser bank, maybe photon grenade launchers, isomagnetic disintegrators, microtorpedo launchers, and other tools of mayhem. Do we have any rules for vehicles in any Trek RPG? But this tank would be fast, mobile, agile, and hostile.
"Retreat?! Hell, we just got here!", annonymous American Marine, WWI
"Gravity is a harsh mistress....", The Tick