Well I was thinking when founding and setting a standard societies got together independently and worked out a common version to teach. At least for the very key signs or alphabet system. Like the ASL is part of the french school so when Goldecia went to develop one for example the main deaf organisations looked to florinthus for example or Llanlanias sign langauge took hold. This would likely be out of a need for them to be intelligible and just pure ease of use. So not so much the states had a role in the development of sign langauge but organisations or schools did instead. If they co-operated a little internationally its easier and makes the language infinitely more useful even if the international versions are more recent.Basically collaberation born out of need and ease.Basically the localized versions are more like dialects which are understandable between each other to a degree (say 80% commonality).
Vote in Voice of Goldecia. You decide!