In the Revelation Climax book of 1988, they quoted Tacitus about Christian persecution but felt compelled to replace his references to "crosses" with "[stakes]", suggesting that the word cruces did not refer to two-beamed crosses at the time Tacitus wrote (untrue).
I don't suppose they ever quoted from Irenaeus?
" The very form of the cross, too, has five extremities, two in length, two in breadth, and one in the middle, on which [last] the person rests who is fixed by the nails. " Irenaeus of Lyons, Against Heresies (Adversus Haereses), Book II, Chapter XXIV.
http://www.earlychristianwritings.com/text/irenaeus-book2.html