> of two already-crashed-on-paper trains.

Exactly.

> Probably like moving one train at a time at <40kph so that there is minimum one ASFA block

If you tell the drivers to move by sight (also <40km/h), you can tell them to all move at the same time, because "by sight" means that the drivers themself can observe objects in their track. They essentially start to move like cars on the road, which they normally don't. Normally a driver does not have an obligation to verify that it is safe to drive somewhere, but then they do. It does not mean that the trains actually move at 40km/h, they can move at 1km/h if that what is required in order to move the train by sight. 40km/h is just the maximum after which it is deemed unsafe to move a train by sight even in the best sight conditions.

> Not only passengers would be angry [...]

I doubt that was even a consideration, that would mean that they would have been aware they ordered a collision, but rather:

> What likely happened was that they didn't think about any of that at all [...]

Yes.