Luckily, the Space Marines won't have to thumb rides when they make it dirtside. As described in the ancient tome, Logan's World is in a corner of space lashed with unpredictable warp storms. As a result, direct Imperial scrutiny is infrequent and fleeting. As it is easier to move a group of Marines without their heavy equipment, a pre-deployed cache of vehicles and supplies await whatever forces are sent in to impose Imperial will.
The vehicle park near Helsreach has six Rhinos and variants in place. Four are standard troop carrier versions. One is a direct fire support version, armed with a las-cannon. The sixth vehicle is a command version with improved communication facilities.
The fire support variant is more than capable of dealing with what passes for armored vehicles on Logan's World.
The command variant isn't exactly spacious, but compared to a standard Rhino, it's quite roomy.
Rumors have it the warp storms are ebbing. The Marines will be coming soon.