Using Zock in cave or place with rough terrain that interfere with hovering would waste its high mobility since it cannot go at full speed [same to Dom]. I would say Zock seems good underwater and in more open terrain as very heavy punch hit and run vehicle [hard to say it as MS

], while Guntank can be treated as gigantic mobile cannon that is not good to put at the frontline but great from a distance for raining hell on enemy targets. Both can be said as support MS[?] but differently deployed.
I think Zock should be used to support Z'gok and/or Agguy variants. It would move on land faster than Gogg in walking or running [not sliding] modes.