Thanks so much
It appears as though none of those include the "obvious" route that I would choose, which would be TPE to Stockport and TFW to Shrewsbury. That can't be the case, can it?
No (you can't just invent routes that aren't in the routeing guide like that!), but the shortest route or one within 3 miles of it are both valid. The shortest route is via Sheffield and Stockport at around 112 miles, but you originally said you wanted to go via Manchester. So you can go that way (Sheffield and Stockport) also even though it's not a mapped route. See the first page of https://iblocks-rg-publication.s3.eu-west-1.amazonaws.com/nrg_instructions.pdf
Just to point out that I'm not the OP on this thread. It was just that it stood out straight away to me that if you said "You're at Doncaster, how would you get to Shrewsbury" my immediate response would be "Sheffield and Stockport" (which apart from being shortest, is the fastest) and that's wasn't included on the route maps that you quoted, which seemed odd.
OK, no that's normal if the "shortest route" rule applies there's no need for a map - Wilmslow to Stafford via Crewe wasn't a mapped route but clearly a valid one for example.
I am the OP so thanks for all the input, when I said "via Manchester", I'd forgotten about Stockport.
Glad we could help you sort this out!
Just to be sure - you have received an itinerary via Stockport so it’s useful if you go that way and anyone queries it - unlikely I think. But if it’s the “any permitted” ticket we were talking about you’re perfectly entitled to go via other valid routes such as Manchester on the day if the desire takes you. Your itinerary isn’t mandatory with this ticket.