Here's the 17 or sixteen if we link Kidderminster and Stourbridge as suggested, so which ones are the real no-hopers and does anyone want to add anywhere else? (I'll regret saying that won't I?)
My feeling would be to drop the East Anglian cities (Norwich & Cambridge) and probably Ludlow too. Bridgnorth and Kidderminster are linked by rail but it's a heritage one and fearsomely expensive for just travelling on so I would drop Bridgnorth too. Those four towns are more difficult to travel to.
Why did we rule out Stafford? And has anyone suggested Telford, or is that too spread out?