Looks like we have an incoming new land vehicle set for Alpha 3.6, the Anvil Ballista with what looks like two variants.
Source: https://robertsspaceindustries.com/spectrum/community/SC/forum/3/thread/new-vehicle-anvil-ballista-german-article
Translated from the German Site:
Official announcement to come sometime in the future...
EDIT: Officially announced now:
https://robertsspaceindustries.com/comm-link/transmission/17153-Anvil-Ballista