Mean Green uses the cheapest made in China units that they sell for maximum mark up.
The reason for the 11 tooth is the starter pinion gear is not on center.
By moving it to one side, the higher number of teeth mesh properly, but are not as close to the ring gear as the 9 tooth pinion gear which is on center.
Both should work fine.
Uncle "Richard" Douglas has a Land Rover with big wheels that never gets stuck... until he breaks something so it won't go. Uncle Douglas always breaks something. - Anna Crowther at the Conclave 2012 (AKA Carburetor Neck)