I am suggesting the BR class 376/0 for Southeastern high-speed for a more variety of stock to see on the map. With the following change of southeastern being owned by the DfT licences might be harder to get. If we could get the 376 we could see it in the following formations 4 cars, 8 cars. I don't know if they operate in the 12 car formation. That's all got this suggestion please like if you want to see the 376 in TSW2
The Class 376 doesn't actually run passenger services on this route in real life (They run services from London to Hayes, Dartford and Orpington due to them being limited to services under 1 hour due to a lack of toilets, although they do run empty from Dartford to Ramsgate via Rochester occasionally for maintenance).
If you're going to suggest a train (even one which doesn't really belong on the route) at least include a photo so people can judge what you're talking about. For many people, 376 means nothing on its own, and it takes mere seconds to steal one from Wikipedia
Also the class 376 is actually a 5 car train, so you would only see it in 5 and 10 car formations. It is also worth to note that the only services the the 376 operates on Sehs are ecs moves to and from Ramsgate depot and very very rarely Gillingham.
They normally stick within the M25 - as they are high capacity metro units. Also I believe they were the last new build train in the UK without Air Conditioning