True. I thought about EgyptAir and Aeroflot cases too. Correct me if I'm wrong, but both planes didn't have FBW flight envelope protection either? That might have prevented pilot/child from upsetting planes attitude irrecoverably.

And EgyptAir co-pilot actually tried to overcome captain and recover till the end.

But I think those cases neither validate nor invalidate the need to screen the pilots?

Certainly they validate the case to have co-pilots.