Space Viking armor is technically a type of combiner. Each set of armor is installed with an Aether Drive, augmenting the already gargantuan strength of the Vikings themselves. The combiner aspect is in their weapons. Each of their weapons has its own Aether Drive installed. This blesses their weapons with all manner of powers such as generating electricity, freezing winds, or even blazing infernos.  

Being giants, Space Vikings can handle their armor and weapons alone. Multiple Aether Drives don’t really phase the big guys. If they were smart enough to build mecha, they would probably be unstoppable. Thankfully that will never happen.