I don't think you will ever get an "exact" answer to your question, as aerodynamic design has so many trade-offs and compromises, and even more so in supersonic aircraft that have static instability controlled by FBW such as Rafale and Typhoon.
As you probably already know, more dihedral gives strong spiral stability which is generally desirable in transport aircraft. Anhedral gives manoeuvrability in subsonic aircraft - one of the reasons the SHAR had massive anhedral.
In the case of two supersonic fly-by-wire aircraft, I suspect you would have to go deep into the original design objectives of the aircraft, and then interview at depth the engineers who set out to meet those objectives. The fact that the Rafale and Typhoon have (apparently) similar flight characteristics shows that there are several ways of reaching the same end result, depending on which compromises the designers choose. I wouldn't believe any "simple" answer to your question!