The ship does have a shuttle bay, its located on the dorsal starboard part of the saucer.
Also the ship doesn't have to have anything rescaled from the way that it is...the bridge doesn't need to be larger, nor do the windows have to be resized.
Its a common mistake to believe that ship classes denote size, which is totally not the case. There are cases that a cruiser would be the same size as a destroyer or even a frigate.
You don't need to be a "small" ship to be a frigate or even an escort. its all about the equipment that is on the vessel in question.
So I think the design and its designation are fine, as are many of the details.
He can make them fit what ever size he want the ship, my point was that right now he has them at three different sizes and needs to make them uniform. I gave him my opinion on where to go with them but it is just that my opinion on it. He is the one who will ultimatily decide what he wants for it.
And I agree that it is the equipment that you want inside the ship that will decide on the size,a shuttle bay requires a large area internally. It was also proven that this class of ship has a bay, it was a fan design that put the bay there. In truth you could alway have a inflatable bay for a shuttle if you wanted to. It lands on the hull in a certain spot and the dome comes out of the hull and closes over the shuttle. You then inflat it and they can come and go from the shuttle.
I will disagree with you on one point though, Classification does denote a size, but since this is a fictional ship we don't know the true size. In any case even in trek a CA is bigger than a DD, and DN is bigger than a CA, etc.