Trains off the S+C often don't connect well with the Tyne Valley services either - there is often a +1/0/-1 connection, so if the train from Leeds is even slightly delayed, you have no chance. The only good thing is that the Leeds train is booked to arrive at the bay right next to the Newcastle service.
Yes, I did the Tyne valley once and found the same. It was nice to do the route, but I wouldn't bother again unless the timetable improved. Quite surprising really considering Carlisle has two bay platforms which are well located for these routes and the double track section to Petteril Junction can hardly be over busy.
Also, one might expect there to be a market for local traffic between intermediate stations towards Appleby and those towards Hexham.