Probably not just training to use all the gizmo's, but more importantly, training in proper decision making. Both for Captains and Copilots.
Decide what mode to use, when and how, knowing what to look for and decide when it does not do what is expected, analyse why and decide on a course of action, possibly to intervene and prevent a situation from developing into something lethal.
In order to make sound decisions, one needs to know the system, but also when hand flying might be more appropriate (i.e. because it gives quicker responses than many a/p systems would).
So perhaps a different approach in training, more away from training for the test?