I don’t think that last explanation makes sense – the overall lift change will be the same in both cases, together with the movement of the centre of pressure.

What must be remembered is that aircraft companies were pragmatic and much less analytical than what we have now. The designers of the Ju87 will have used the seperate controls surfaces because they knew it worked: they had a backlog of experience and a considerable database to work with. Yet they abandoned the system for subsequent designs – I suspect this is because of the higher drag of the approach. The Ju87 was not a very fast aircraft.

The lightness and balance of the controls was not specifically due to the approach as opposed to any other, but to Junkers’ experience with it. Other companies managed similar qualities with more conventional controls. And others didn’t, of course, but that was part of the learning process of the time.