My preference is to let the generator do my bulk charging, short and sweet, quick and dirty, with the generator, and the solar panel can do the top charge last 10-15% the rest of the day while the sun is shining. Let each system do what it does best, and most efficiently, for charging purposes. Bulk is bulk, run it hard and fast, get 'er done, get that generator turned off ASAP, then let mother nature and solar panels take care of the gentle portion or cycle of the battery charging regime, the top charge. Let the two systems do what they do best, a gas generator off the grid is not efficient top charging... never has been, never will be. Solar or on the grid is good for top charging.
That is some of the best info yet! Could not have said it better myself.