I have shown you historical evidence that Jesus died on a cross shape, not on a "T shape". I think the earlier Christians who lived in Israel know it better than you, don't you think?
None of the earlier Christians claim the cross to be the symbol of Christ nor his religious movement. And let us note that not even yourself in your own post makes such a claim. Your argument in that post is that the cross is interpretable as a symbol for Christ, not of it being in factual, widespread use as that symbol during the early years of the church.
Note how your sole evidence in favor of there being such a symbol at all in early Christianity is one that mocks Christians and denigrates their faith - do you really believe that is a sound argument in favor of Christians having adopted this symbol of their mockery as their own, especially in the face of evidence of other, much more widespread and popular symbols?
Sorry, but why do you think God chose the cross as a sign? I would rather say that the sign was that Jesus was dead three days and then raised from the death.