This is just a guess: maybe thought experiments? In law, that might be randomly picking/generating cases and arguing the points to rehearse knowledge. In history, similarly it could mean role-playing historical scenarios and considering the individuals involved and the politics of the day.

I'm imagining these as group activities, not something one would do alone.

I also freely admit my naivety regarding these subjects.

Finally, I don't think these or similar approaches are "short cuts". Quite the opposite.