"From East Croydon, use the x25 or x55 to London Bridge which connect with the Overground service to Highbury & Islington on Platform 1. "
This is technically correct, but if you happen to catch the x03 or x33 from E. Croydon to Norwood Junction, then you'll be dumped off at platform 3, along with your prams, luggage, mad relatives and wheelchairs.
All these slots could all be randomly rearranged at the next change of timetables and unless there has been a recent operational change, there is no announcement made at E. Croydon of the suitability of one train over another. Not their concern.
It is a very poor show.