Can't help but agree. Indeed this bit jumped out at me...
...because I experienced an issue with exactly this at Leicester on Saturday. Two trains, departing minutes apart, were sharing different ends of a platform. The platform dot matrix displays were only able to show one train, and from the entrance to the platform the ends of the trains were not visible, so arriving passengers were unclear which was which. With a bit of inspection one was XC and the other, further away, was EMR, but the respective 170s don't look dissimilar at a glance and I'll confess that it took me a moment to figure out what was going on - other daytrippers, in a rush and less familiar with TOCs, were far more agitated and were queueing up to ask the harassed conductor which train was which. A couple of platform side screens on the train would have saved a lot of collective stress and some crucial minutes!