With the current netcode of this game, anything "random" in high-level encounters is just not feasible.

It would be impossible for many a player to react in time and reliably be able to dodge. Most players who beat Titan are able to do so because they work around the positional update delay and delay in client sync by memorising the whole pattern of Titan's moves. This is the design of all high-level encounters in ARR: 100% predictable patterns, unlike most MMOs which add some level of randomness/scripting.

I don't see how this could change in ARR short of completely revamping the netcode and server-client sync/authority processes.