I think some of the difference is that although the full backs still get involved, it's more the position they get involved in. When we have the ball Pickering and more likely JRC tend to drop into the deep midfield position. This creates two things; it gives the central defenders an extra option there and strengthens the midfield position. But it also means that they won't be boxed in if they receive the ball in a traditional full back position. What was noticeable earlier in the season was that teams would press our full backs there once they received the ball and had nowhere to go.
Obviously there's far more that's changed leading to our upturn in form, but this is one tactical tweak I've noticed really since Rotherham.