The discussion was the appropriate use of game sims in training. Game sims are very useful in expensive training to get basic operations skills and certain techniques down, but they tend to have certain flaws, due to the nature of how we design the sims.
If, for example, we expect to be continuing operations in certain desert and mountain terrains, which we will (unless something happens), we need to account for the actual extremes in actual operations in those climates.
We can do those in sims, to a certain extent, or we can realize those work better in actual physical training exercises supplemented by sims to teach basic operations, basic faults, highly likely combat impacts (stoppages and immediate actions), and highly likely environmental impacts (excessive heat, visibility and temperature control failure).
And, I served. Carp happens. Sims only work so far. Failure to train for that leaves one vulnerable, or like the stupid movies and commercials walking on a ridge so that everyone in the world can pick up your exact location from heat IR UV and basic line of sight silhouette optics. Or driving an armored vehicle into a bad situation you could have avoided.
Who do you think was in Afghanistan when the US Army bugged out off mission to Iraq? It wasn't unicorns, that's for sure.