Interesting point you bring up.
The BOA sheeT (and likewise WGI) dictate specifics for certain point ranges, using “vocabulary” (good/great/outstanding…some/most/all of the time) to guide the values they award. UIL has a variance of this, but not to the same degree.
some additional causes for variances: using ordinal numbers to determine final score, music/visual caption swap for finals, random draw for finals. It must be said that judging is subjective and there will never be a great way to do it, only means of trying to do it better I guess!