I was merely suggesting that the 8 or so 700/0 units used on GN services would be more suitably deployed on metro services. There is very little need for a class 700 style interior on the Cambridge stopping services, and none at all on the fast services out to Ely and Kings Lynn.
The Cambridge-Kings Cross stopping trains are the Hertfordshire metro service. They serve 6 towns within 20 miles at Hatfield, Welwyn, Stevenage, Hitchin, Letchworth and Baldock. There is a lot of intermediate traffic between these towns, especially students going to/from Hatfield and Hitchin. Furthermore it has significant flows to and from both ends of the route, because of the amount of traffic that there now is to/from Cambridge. Taken together this means that lots of station stops involve significant amounts of both alighting and boarding, and this is where class 700s really score in terms of passenger convenience and reducing dwell times.
Looking ahead, the Ely-Royston section is also getting much more like a Cambridge metro, and this will be boosted further when Cambridge South opens next year.
I am pleased that even though the initial premise of my question was wrong, it's generated plenty of discussion.
Going back to the original branding question, in 50 years of experience of travelling between the Fens and London, only two operators have had a strong brand,
Network SouthEast and
First Capital Connect. But the Cambridge-Kings Cross route has also had two very successful brands, the
Cambridge Buffet Express and the
Cambridge Cruiser. The latter is still in common usage although it has had no official status for about 20 years.
The Cambridge-Brighton service is a relatively recent addition and is rightly part of the
Thameslink brand, which has the core at its core! But the Great Northern brand is weak: next year's opening of Cambridge South would be an ideal time for a relaunch with 2 good route brand names that could be operated together. The rural Anglian branches have a long tradition of route branding operated together and is an example to learn from.