Won’t be a 172 until the Nuneaton branch has one.
That line does need extra capacity at the peak times. ‘Sardine’ conditions is an accurate description. Even on the tube you have space to breathe at rush hour!
Fair point on the XC being full. Whether the passengers will appreciate a downgrade to a dogbox is another matter. What proportion travel onwards from Leamington or do they all get off?
I got on the 08xx Coventry arrival from Nuneaton not long ago. Only just squeezed everyone in the door at Bedworth!