If you had watched the Real Madrid vs Osasuna match at Santiago Bernabeu, you would have known that it's not because Real Madrid has a new coach that made them win against Osasuna by 1 goal to nil. In my opinion, Real Madrid struggled to score goals against Osasuna because Real Madrid midfielders weren't creative enough against Osasuna, and even though Real Madrid got used to Xabi Alonso's pattern of play and Real Madrid midfielders continued to perform the way they did against Osasuna, Real Madrid will have problems scoring goals this season.
I think that it's still very early to be judging this xabi Alonso side because it's still early days, do not forget that his Bayern Leverkusen side was a higher scoring side when he won the league unbeaten, so am very sure that once this real Madrid team blends to his playing system, they will surely band in the goals without troubles.
As for the midfielders you are talking about, I think that it has more to do with understanding what the coach demands from them, once they can get it right, they are surely going to comes good especially against a smaller opposition like osasuna.