Drag and drop is very intuitive and can be great for lots of things.

However, something like setting up large routing configurations may be faster using an old-fashioned matrix with inputs across the top and outpts down the side or something.  Then you’d just click the boxes where the I and O intersected.  You could add intelligence to prevent illegal routings and such, but an approach like that might make setting up the initial config faster.  Then you could use the graphical drag approach for the special cases or to tweak it.once the base configuration is set.