This is something that should have RNG applied to where the object appears, not whether it appears.
In a guild-versus-guild competition where every advantage is multiplied by 30, the basic contents of the rooms as a whole should not be different. By this I mean in the 25 levels every guild should have the same number of “premium” scrolls. A guild that is gifted an extra luck scroll can score an additional 60 dooms over another guild with an otherwise indistinguishable performance. This is a huge unfair advantage.
Winning or losing because RNG gives an extra Valraven or two is bad enough, but not normalizing the floor contents across guilds leads to very lopsided results.