Mars Lander? I think I fully simulated it, Codingame's Mars Lander 2 Test Simulation
Run it and you'll see both the CG output and my simulated state. Note that the simulated state only copy game state at turn 0, from there it's fully simulated, and as you'll see the simulation doesn't drift over time.
But this is nothing nowhere as harder as Poker Chip Racer. PCR has collisions, absorbtions, with chained absorbtions, collisions against walls after absorbtions...,... really hard to do it accurately, yes. Took me weeks.
So yes, I agree that having all referees is a good thing (all of them, not just simulation based ones).
This is good also to reduce CG's server load by testing things offline.