GAW,
I was not c”v saying to throw out the halacha, I was merely suggesting a possible reason why the RS”O arranged things this way. The basic idea which I expressed about avdus is something which I heard in the name of a gadol (whose name I won’t mention because I can’t confirm the statement).
The Ralba”g is not saying that the relationship between man and wife (as he describes it) is a halacha, it’s a law of (human) nature.