Eckard
Your representation of what I am saying, generically, is incorrect.
As I have said many times, the precise details are irrelevant to the form of the argument. For example, how many affected photons constitute a 'light', ie something that gives us an image, how this affect is effected, how it travels, is the light which travels in one direction physically identical to the light which travels in another, etc, etc, etc.
The simple fact is that light (whatever it is) travels (however that occurs). And there is a sequence of them. That is all we need to know, in order to make the statements I make. Your argument is like saying one needs to understand how a bus works in order to make the statement that it is something and it is moving.
The comparison was between light and earth, forget all the intricacies about what is actually involved. By definition, as both are moving entities, then the result obtained by comparing one with the other will differ depending on what particular comparison is effected.
Then the next point is, does any of this have any actual impact on relativity as constructed anyway. And the answer is no. Because the flaws in relativity have nothing to do with observational light. In fact, there is none in relativity. You find me a specific reference to observational light, not observer frame, etc. The light he does refer to is a timing device and we get lightening, light beams in clocks, a ray of light which is equivalent to the man walking on the train, etc The two realities which exist, ie reality and the light based representation thereof, have been fused into one. So there is no observational light, an 'observation' is deemed to be 'existence'. Which is why when he attempts to describe his arguments by example, he involves some form of light, which is effectively performing two roles, ie it looks as if it is observational light, but really it is a timing mechanism.
That said, as I have always said, what you are specifically saying re M&M may well be good stuff, and we ultimately need to know it.
Paul