the traditions were all in flux
I don't believe the evidence supports such a sweeping statement. People make mistakes. Irenaeus' writings were not inspired, infallible or perfect.
From Orthodox Christian Theology:
"There are several problems with Irenaeus’ chronology. First, secular historians are aware that Pontius Pilate served specifically during the reign of Tiberius and perhaps the very beginning of Caligula’s reign—not Claudius. Additionally, this obviously does not align with modern conceptions of the Lord being approximately 33 years old before the resurrection.
Most importantly to those looking at the earliest Christian sources on the question, Irenaeus’ chronology does not match that of his contemporaries. Saint Justin Martyr, writing before Irenaeus, placed the Lord’s death under the reign of Tiberius. (First Apology, Chap 13) Saint Hippolytus, writing a generation after Irenaeus, explicitly held to a chronology of Christ having an approximately 33-year life before the resurrection. Other near-contemporaries such as Tertullian (Apology, Chap 21), the author of the Acts of Pilate (Prologue), and Julius Africanus (Fragment 18) concur. Hence Irenaeus is contradicted on this specific chronological view by a consensus of Christian saints and thinkers in his own time."
But none of this changes the overwhelming evidence that Jesus was crucified on a cross and not a pole. JW's just love being contrarians to bolster their pseudo-intellectualism.