Hi Neil,
Your ancestor's story sounds very credible to me, I've discovered that my family moved around just as much, and, like me in the twentieth century, they were going where the work was.
Shoemakers were probably having a difficult time by 1871, not only were there railways for him to use to move to a new town or city, but the railways were there for his cutomers to nip smartly into the nearest town, buy a pair of boots of the latest fashion, do some shopping and nip home again! The village shops were losing ground, too.
My family includes a John Salthouse who was a shoemaker, I have no reason to think that he had any more money or income than anyone else, but when his wife took ill with TB in 1875 she and her eldest daughter went to Southport, presumably for the air; she died there and her body was returned all the way back to Alderley in Cheshire for burial, so it mustn't have cost too much! John seems to hae become a labourer in the village suggesting that there wasn't enough work for two shoemaking families any more The 1871 census shows that his two eldest sons had moved to Liverpool and Salford to find work.
Perhaps your guy found work as a shoemaker in Northampton then Liverpool - and Wallasey was always the next move if business was good, especially if he was ready to retire!
I hope this is of interest to you, I was surprised myself when I found out how much use my family made of the railway network
Best wishes
Hilary