The confusion among the JWs is actually a very telling mistake.
The Jews of the Second Temple era spoke Aramiac, mixed with Hebrew. The Romans spoke Latin. But the official language of writing was still Greek, the language of Alexander the Great who, though a Greek, paved the way for the Roman Empire and was still highly regarded after his death.
However holding on to Greek as the literary language was much like the use of Ecclesiastical Latin became centuries later. Most people in Rome didn't read, and those who did may have read only vernacular Latin with enough Greek to get by. And Rome had invented new technological advances, especially in warfare, that didn't exist in the Hellenistic world of Alexander and had no Greek words for them.
So the gospel writers used two Greek words for the cross, since the device did not exist in Alexander's time: STAUROS and XYLON. The first word meant "pale," a simple stake upon which criminals or their heads were sometimes tied or nailed to, and the other word meant "tree" in the sense of a dead tree trunk. The "T" shaped device had no word in the Greek at all.
The Witnesses, having no language scholars or background in history, simply opened a lexicon and read that the Greek word, STAUROS, meant "pale or stake." So they claim that the Devil and his Christian minions hide the fact from the world that Jesus really died on a stake. I mean, you can look it up for yourself in any Greek lexicon and verify it for yourself that the Greek word STAUROS does indeed mean "stake." Argument closed, right?
This is where being a language scholar is so important. Scholars know that the events described didn't happen in a Greek-speaking word. Jesus spoke Hebrew-Aramaic and the Romans spoke Latin. When the Romans pulled out the device upon which Jesus was nailed they called it a "crux," and there wasn't even a Jewish word for it then.
Because the official written language of the Roman world was Greek, the gospel writers did what you always do when you translate things from one language to another: use the best equivalent you have despite the fact that you will lose something in the translation.
Besides, we have evidence of crucifixion, secular accounts, etc., so why wouldn't anyone not understand these things?
Well, JWs obviously get blinded by that egotistical view "I looked it up and saw it with my own eyes, so I know the truth." The problem is that unless you know how to use a lexicon along with etymology then you will make many mistakes like the JWs did. It takes a translator, an etymologist, and a philologist along with a cultural specialist and a theologian who is an expert exegete in order to properly translate any Scripture text. That's a lot of educated specialists. Anyone can look up a word in a book, but it takes trained critical thinkers to put the data together properly, and the JWs have none.
The JWs missed the logical step of remembering that Greek is merely a translation of the events and that the words used were archaic or at least not always compatible with what was happening in the first century. Anyone can look up anything in a book, but that doesn't make you a scholar unless you can use it like a scholar.