If we keep the wind availability aside (meaning that we assume it to be a very good windy site) and just want to determine practical max power such a machine can make, even then magnet size and grade, rotor diameter, coil wire size/guage will be governing factors....
And as such a correctly designed, sized and fabricated dual disk rotor generator with 24 numbers (12 on each rotor) 2x1x0.5 inch Grade 35 Neo magnets can go for 350-500 watts sustained output....IMHO