So, we were doing LK 25 man normal (i know, thats horribad), and we actually had some very nice early attempts in.
At one point in the evening, my DXE timers were saying that defile was first, so we spread for it, but our luck was that timers were off and it was valkyrs first.
So later on in the evening, where we've been having those valkyrs first (its the 2nd one that comes in p2) all evening, we suddenly start to get defile first. That lasted rest of the evening, and caused us to be caught off-guard all the time, and no kill for us ..
So why is this? Just RNG or simply a design mechanic that can screw up timers?