Here are a few options:
- limit # of sbs VR can field (consider a similar limit to how superweapons are currently limited)
- limit them to move only btw phase nodes
- consider making a tech in the diplo tree that has to be researched btw 2 VR players b4 they can have moving sbs. Means they have to get envoys/certain amount of diplo points first
- make it research lab dependent
