The Zubr Transport is the Soviets' amphibious transport vehicle.
The Zubr is the Soviet amphibious transport, capable of ferrying large amounts of forces over water. They can transport both infantry and armor to any location and keep it out of harm's way. Though these transports are armed and can swat away light or half-hearted attacks from both ground and air, they should not be put in harm's way to prevent severe and unnecessary losses as they are not as hardy as the animal they are named after.
The Zubr still plays a big role in the case of the Soviet forces having Borillo/Armadillo. Although Borillo/Armadillo can help a lot in the surprise attack, it can only transport infantry, and armored units must board Zubr if they want to cross the waterzone.
Voyager is also equipped with two flak cannons that allow it to self-protect in small attacks and get out of danger area as quickly as possible. But equipped with weapons does not mean that it can be used in combat directly. The flak cannon is only effective for light armor units and basic infantry so that it cannot replace other formal combat units.