Hi.
I won't be going into details with the PM, how many poles, etc. It's just a detail, compared to my main point:
why do you want to use a gearbox?
Many people complain about the soft 'woosh-woosh' sound some blades make. Now, add that gearbox, and even -you- will be complaining about the noise of your own windgenny. Not to mention the wear of it and the maintenance. It's just the noise that would be my main problem.
The Dans have explained, over and over, why you don't want to use a car alternator, or use gearing.
Just my opinion. If you just can't resist tinkering, go ahead. If you want maximum power with minimum effort & frustration, do what the Dans have done & build an axial flux, or do a motor conversion à la Zubbly.
As to the poles in your drawing: they seem to be pretty close to eachother, so you'd be getting some magnetic-field cancellation (a magnetic shortcircuit between neighbouring poles). But, again, this is just a detail compared to my main worry, the gearing. Do a search on this board for 'gearing'; I don't remember reading a story on this board about converting a car alternator to a PM alternator.