It feels like there needs to be almost as much diversity in surface vehicles as there are for ships. Would imagine that, when more planetary environments become available, we'll either be able to submerge into large bodies of water in the ships or alternate a surface vehicle with a water-going and/or amphibious configuration, too.
Perhaps even vehicles which are capable of burrowing and tunneling beneath soil.
In any case, it would be nice to have a more combat-focused, armoured vehicle: Less cargo space, better survivability.