Both randomness and scripted have pros and cons. I can think of a few times where Imdugud did nothing but heat lightning-charge (no tether-charges) and that made the fight easier. So even with randomness there is a real possibility of getting the really lucky set of mechanics and a really unlucky set of mechanics. Then ppl would be complaining the fights arent fair cuz team A got "lucky" or team A just wiped until they got the "lucky" string of mechanics.

Even randomness has it's drawbacks.