I'm not sure AMG was the best fit, personally Polaris would have been the best imho. AMG while producing great cars, have a large but largely atrocious dealer network with ludicrous pricing and who wants to buy an m/c from a car salesman/showroom. It's a different dynamic.
While I can agree that Polaris might have been a better choice, its safe to say that MV would not be sold off the same floor as AMG cars. Ducati is a stand alone brand in terms of retail/service dealer network. Integrating MV into MB dealer network would be a very costly proposition, it wouldn't really make any sense from financial or marketing standpoint.