alt Hacker NewsThere is a much better way of doing this which some professional cameras do called pixel shift. It shifts the sensor a tiny amount in between multiple exposures to compose in to an absurdly high resolution image. The downside is it only works on a tripod since you need the camera perfectly still.
The obvious issue with multiple cameras at different focal lengths is they won't all cover the frame of the widest one so only parts of the image will be sharper.
But if this matters to you, just get a full frame camera. Any 33MP full frame will blow away a 200MP phone camera in sharpness and detail.
I wasn't thinking so much about resolution, but rather all the other things it might allow. Re-focusing after taking it, for example. 3D by default, since the width of a phone is basically the distance between your eyes. A host of other things the much-more-high-powered CPU on the phone can do compared to a camera.