Arfa Daily wrote:

Whilst the magnitude of the current in all diodes is theoretically the
same

It IS the same.

- and even that might not be quite true if there is any residual DC
magnetism in the core of the transformer

Any residual magnetism won't affect the load current one tiny bit.


- the current which flows in the diodes in the negative arm, flows in the
opposite direction to that in the
positive arm.

So what ?


Also, the arse end of the diodes in the negative arm,
typically go to the chassis mass, which may well be tied to power ground
(mains earth) so I think that there might very well be a "possible
scientific explanation".

No, that would be voodoo thinking.

Check out Kirchoff's Laws.

Graham