Yeah of course it applies to Wonder Woman too. But i don't try to bring her down a notch, i try to bring her up millions of notches as it stands, all i am saying is that i don't think if Superman and by extension Supergirl could lift the eart and Wonder Woman just the venus, but as trade off could Wonder Woman fight at 3,3 times the speed of light in an effective way and Superman and by extensions Supergirl just at 3 times the speed of light. I am well aware that Martson has specifically said all the strenght of Superman, but i don't even think he would have a problem with my proposal.
I however have to disagree with this, DC has contradicted their own words often enough, and by the same token would it be head canon without too much basis to talk about modern Supergirl being stronger than modern Wonder Woman, especially by looking at who is portrayed as the strongest female superhero with statements and suggestions from DC.
And i have also disagree about the rest, because you are not talking about Superman being physically a bit stronger than Wonder Woman, you are talking about outright making Superman superior to Wonder Woman because he would b otherwise allegedly inferior due to his weaknesses. This is strongly contradicted in a time were it has been not long that Wonder Woman's often existing weakness to weapons of the piercing kind, was going so far that get shot by regular bullets got portrayed as life-threatening event, even in a very bad context scene were the same bullets first bounced off Superman and with the incredible silly explanation that Wonder Woman could not react to indirect attacks. And if we are honest, being outright inferior puts Wonder Woman not even on the second but often enough on the last place of the heavy hitters in the Justice League in modern times, which opens another can of worms. Last but not least should be Superman's weaknesses not even common enough for this argument, it just sometimes looks like that because of bad writing, red suns should be no typical problem for obvious reasons, kryptonite should be a very rare material, and magic is not even meant to be a hard counter in general like any Superman fan could explain. In fact should Superman outright lose any direct enconuter with Wonder Woman if magic would be a big enough weakness to jusify making Superman superior, Wonder Woman is a magical beig, with magical weapons, who even uses more dire magic like Zeus magical lightning now and then. But even Shazam or Black Adam are just portrayed as threats, but not as certain loses for him.
Of course has Wonder Woman bigger problems, but the idea of making her outright inferior to Superman is part of the same problems, and Wonder Woman's fights with Doomsday as example, or half canon/alternative world fights with Superman or Bizzaro as other example are usually more impactful and worse than the few times Superman jobbed to Wonder Woman villains. I am talking about storylines like this blatant insult to Wonder Woman as a character as example:
This is also not truly a good argument in this case, looking at Flash's stupidly wide array of speed force powers and possibilities like the infinite mass punch, is Cheetah like she is portrayed most often far more of a character who can only do that one thing than Flash himself. And as a physical challenge would she just make sense in a higher echelon of speed than Wonder Woman or Superman, and i don't think it would be unfair to let her crack the speed force level in parts because she has still far less powers. It could get even explained with divine magic, the god wave was even the source of the speed force in the past, and we saw full blown gods like Mercury/Hermes do things like speed stealing: