Platforms? Different heights goes back before 1948 nationalisation. This is trains that can't rescue another because couplers are at different heights.
I'll check the new one I heard about, but companies have had to have "Thunderbird" locos stationed at various places to rescue failed trains, with adaptable couplers.
BR "standard" locos were designed by R A Riddles, largely based on LMS designs, but using standard components so you didn't need separate stock for each design.
The main deviation came with diesels, when every region went for diesel-electric, except the Western Region which went for diesels with hydraulic transmission. But you could still couple them together. This "AI generated" story must have been written by a Western Region AI system: "The mechanical skills required for maintaining hydraulic transmission are more similar to those available in the mechanical sector. This made diesel-hydraulics more appealing than diesel-electrics in Britain, which would have required a new discipline of electrical engineering."