How do the ‘Order’ cancel the ‘Ra Trial’ in IX?

I mean what happens if the ‘Chaos’ crew don't succeed in the Trial? We know the Trial can't be undone without completing it, as the Zeus Trial kept going long past Perseus' failed attempt.

And we can assume the Order don't know squat about how to complete it ─ because then they'd have no reason to use prisoners.

So, do they just risk it? “If these illiterate slaves don't complete it, I guess we'll just stay frozen in time ─ for like, forever.” Do they not account for failure?

The ‘Chaos’ crew's attempt is a dream, so it obviously doesn't matter if they complete it or not ─ but I mean, like in 30 BC, when they were actually tinkering with the Sentinel Artifact. Did they not account for the slaves dying in the process, and them being stuck in time?