Those maps are taken from Francesco Forgione's Mafia Export. A stunning read.
Visible presence doesn't always equals power. I meant actual, overall and structured presence. Milan and Rome are the cities where the big money is to be made. Milan has a larger drug market than Naples, not to mention multi-million euros crooked deals in construction, movimento terra, etc...
These two cities are the Capitals (financial and political respectively) so the biggest scams have to start/go through/end there.
One more thing soldiers-wise: keep in mind that these cities see the constant activity of all 4 Italian oc groups combined.
