Is it? I don't think so. But, I am also a full BiS high-parsing player who cleared A12S on week 4 or 5. I think Thordan EX and Sephirot EX are clearly harder. The ordering of the rest is debatable.
As for Zurvan, like I said, it is a step in the right direction. You want content that tests players even if it's not hard content overall. Zurvan tests if you can do a proper opener. Just look at the discussions about soar skipping. It's exposing the hard truth that a lot of people can't do a proper opener and it's forcing people to really care about DPS like they should (though a lot of people in this topic still have their heads buried in the sand). With how punishing the mechanics are, it's actually forcing people to execute well. Compare that to Sophia EX where DPS didn't matter and you could repeatedly botch mechanics and still comfortably clear.
Earlier, I said Zurvan is really nothing new in terms of mechanics. But, from a different PoV, it does familiarize people who aren't seasoned raiders with common raid mechanics. Bait and move mechanics are all over savage. Prey marker isolation mechanics are all over savage. Out-in mechanics with no indicators are all over savage. Dragon Rage damage sharing is all over savage. Assigned position spreading is pretty much A11S's bread and butter. If you aren't familiar with T11, Zurvan's tether system will at least familiarize new raiders with a partner system they will see again in A12S. Zurvan is actually similar to Thordan in how it's a fairly succinct summary of common raid mechanics.
From that PoV, Zurvan is a better raid progression fight than a lot of EX trials which have more unique mechanics -- Sophia EX for example. Your complaints about the broken ladder is not that relevant to 3.4+. It was a really pronounced problem in 3.0 and 3.2, though.