What exactly is our magic trick though? Lucho's system is perfect at the moment and doesn't have any clear weakness. The only real weakness we had was earlier in the season Busquets was getting caught too far up and teams had success counterattacking us through the middle because we had a hole- whether they meant to do it or not. It depends on the form of the players, of course, but we are in great shape.
We aren't really weak to counters anymore with LM and RM covering fullbacks, yet Iniesta and Rakitic have creativity when they aren't forced to defend and the fullbacks aren't far up the field.
When they are sitting back defending, our fullbacks are adding width and while the best front trio in the world is wreaking havoc- all can score, all can penetrate, all can create. As long as we have these great, world class talents all we have to do is stick to what works, as long as they are willing to keep themselves in good form.
2-3 new exciting signings aren't going to fix that, because once again, who knows if their form will be good either? The only thing, and yes ONLY thing good about new signings at the moment is that it brings new blood and new drive- all our new players from last season have already tasted success to the highest degree. New blood keeps the team hungry.