Right-hand drive on GWR and LNER?

I've been puzzled by something for a long time, and I'm hoping that someone reading this may know the answer. Both the Great Western and the London & North Eastern designed steam locomotives with the driving position on the right-hand side, while signals were on the left. Now this was in a period when the Chief Mechanical Officer of a railway had virtually absolute power over equipment design, and everything on a locomotive was placed exactly where the CMO wanted it. That being the case, why would they design a locomotive with the driving position on the right? I know there was a memorable near miss at Northallerton directly attributable to the fact that the driver failed to see the distant, outer home, and inner home at caution, danger, and danger, respectively, owing to the boiler being in the way, but clearly saw the starter and advanced starter much farther ahead, both at clear (but for the other train coming in from the left), and only the sudden realization by the driver of the train which had the clear route that the train to his right was not going to stop averted a sideswipe. I have read a fairly extensive report of that incident, as well as other references to such locomotives, but none have stated a reason for putting the driving position on the right, or even a mention that it was unusual. Any idea why this was done?

This is not an answer to your question, but South Africa also has the driving position on the right and the signals generally on the left, so South African steam drivers also have problems sighting the signals. The rules say that the fireman must also look out for signals and confirm them with the driver. This is usually done with hand signals, as the noise on the footplate, particularly when using a mechanical stoker, makes conversation difficult. Having the driver's position on the right certainly makes it a bit easier for a right-handed fireman to swing his shovel, but I doubt that this is the reason for it, particularly as ergonomics was not a high priority in those days.

Kenya, on the other hand, has right-hand drive with the signals located on the right, so the driver has a clear view of the signals.

pretty sure that was the case in New Zealand too , it does nt make sense , as it would also make it difficult for the driver to see the passneger platforms on the left , so there must be a reason for it .