As far as I know these older aeroplanes were not so heavy (fabric and wood) and they have had double wings. So I can imagine, that ther were more sensitive to wind, thermal and so on. And so it is more difficult to hold the position / formation. And not to forget the early engines (rotary motor). Perhaps the AI-behaviour simulates all these factors in every flight with every aeroplane, without differences. But it's only a supposition of mine.

Greetings!