It took me several tries as well to get through there. The tanks really decide whether you succeed or fail that one. An inexperienced tank plus that impatient guy who always has to go dashing in the moment an instance starts usually equates to a fail and a free trip back to the queue.

As an educational experience, it's very poorly designed. One fail and you're out, rather than giving the team a chance to regroup and adjust like you would have in pretty much every other piece of content. Guildhests function a bit differently than dungeons though, so it's probably a technical limitation.