[Autumn]

One could argue its the nature of RNG, but when 4 people are all rolling at once, it starts to feel unfair when the above scenario occurs, but at the same time if you have 4 people in a party and it rolls a 9 star, everyone there gets the same 9 star, which can inflate the amount of items in the game all at once.

Though this may or may not be the intention of the OP, I will specify that I think that at the very least the amount of rewards received can all be the same, that way the above scenario doesn't occur and introduces up to 4 dragon king helmets/terrasque shells all to the game at once.