Table world.gameobject does not contain any field containing scale of gob. Gobs have scale set only in gameobject_template. So it is most likely not possible at all to set a scale to only one gob - you need to edit template value, and thus edit scale of all gobs in the world. Rescaling gobs also isn't anything I would like to do without restarting a server, because changing their scale means that their collisions ar also being rescaled and thats not something I would like to do when players are messing around.
This would be far more work to be done than just creating command itself - you would have to implement system which would be able to give gobs with same ID scales based on scale in gameobject table rather than one template scale from gameobject_template table. I am not sure if it is even possible. Probably yes, easy? Probably not at all.
Just btw, I have never seen scaling command for gobs anywhere. For characters, NPCs, sure, but never for gob. Well, I have always worked only on TC and mangos servers, whatever.
