I've been there many a time, and feel your pain, I've also been on the ones holding you up as well, and its...
One train that we run of note is the Victoria to Southampton via Horsham and Barnham. If your a bit late, when you get to Ford junction you glance out the window. Option A: The Littlehampton to Portsmouth stopper is waiting, its yeahhhh. Option B, its gone.... your doomed, slow, slow slow, punters for Fishbourne etc, missed connection, next train, an hour. punters connection onto the GWR train to Bath and Cardiff via Westbury, missed, (heading to Devon or Cornwall, you could now be hours late), chances of making it to Southampton, poor.
Meanwhile your working the LIT to PMS and the VIC to SOU train is late, as your at Fishbourne, Nutbourne etc (and mainly on Red so no fast getaway), all you can see when you look back is the headlights of the train knowing that option B is happening there and then, and that's all the way to Farlington junction.