There is adjusting the style accordingly, and then there is finishing in bottom half when it come to goals scored. They won the title though, but it must have been incredibly boring.Van Basten was out for most of the season and they adjusted their style accordingly. You'll probably never see such a good defence, almost certainly the best ever assembled, paired with such a weak attack again.
I guess just Capello being boring Capello. On the other side, they put 4 past Barca in the final of UCL (and apparently were not that bad that season there, scoring 21 goals in 12 matches.