Some say dome shield are dependent on owning an amp station. AA gun is for when there is no amp station.
I really don't think the dome shields are necessary for hossin, considering just how many trees are there for cover both directions. A wide open continent like Esamir maybe, but Hossin definitely does not need them.
Why are there dome shields on Hossin anyway? the trees already provide a ton of cover. Add dome shields to Indar and Esamir, trees to Amerish and Hossin.
Last I checked their official response was that the dome shields shouldn't be there atm, remember, this is not a live server, it gets stuff in various states. They're still working on the concept of dome shields however, it's just not ready yet.