Tertullian, whom the Jehovah's Witnesses quote from when his words fit their teachings, mentions the shape of the cross Jesus was nailed to almost two centuries later:
For this same letter Tau of the Greeks, which is our T, has the appearance of the cross, which he foresaw we should have on our foreheads in the true and catholic Jerusalem… (Adversus Marcionem, III, 22)
Jesus would have died within hours of suffocation if he were on a stake. The broken legs are a clear indication that he did not die in such a manner-on a stake. Also one other thing to note is that in Ancient Rome the common style of execution was that of being nailed to a cross.
Here is one account among many ancient writers back then:
Dionysius of Halicarnassus (first century B.C.) described this ancient practice:
"A Roman citizen of no obscure station, having ordered one of his slaves to be put to death, delivered him to his fellowslaves to be led away, and in order that his punishment might be witnessed by all, directed them to drag him through the Forum and every other conspicuous part of the city as they whipped him, and that he should go ahead of the procession which the Romans were at the time conducting in honour of the god. The men ordered to lead the slave to his
punishment, having stretched out both hands and fastened them to a piece of wood (tas kheiras apoteinantes amphoteras kai xuló prosdésantes) which extended across his chest and shoulders as far as his wrists, followed him, tearing his naked body with whips" (Roman Antiquities, 7.69.1-2).
Seneca (c. 4 B.C.-A.D. 65)
(6) *** refigere se crucibus conentur, in quas unusquisque vestrum clavos suos ipse adigit, ad supplicium tamen acti stipitibus singulis pendent; hi, qui in se ipsi animum advertunt, quot cupiditatibus tot crucibus distrahuntur.At maledici et in alienam contumeliam venusti sunt. Crederem illis hoc vacare, nisi quidam ex patibulo suo spectatores conspuerent! "Though they strive to release themselves from their crosses---those crosses to which each one of you nails himself with his own hand--yet they, when brought to punishment hang each one on a single stipes; but these others who bring upon themselves their own punishment are stretched upon as many crosses as they had desires. Yet they are slanderous and witty in heaping insult on others. I might believe that they were free to do so, did not some of them spit upon spectators from their own patibulum!" (De Vita Beata,19.3).
(7) ....alium in cruce membra distendere.... "another to have his limbs stretched upon the crux" (De Ira,1.2.2).
(8) Video istic cruces non unius quidem generis sed aliter ab aliis fabricatas: capite quidam conversos in terram suspendere, alii per obscena stipitem egerunt, alii brachia patibulo explicuerunt. "Yonder I see crosses, not indeed of a single kind, but differently contrived by different peoples; some hang their victims with head toward the ground, some impale their private parts, others stretch out their arms on a patibulum" (De Consolatione,20.3).
(9) Contempissimum putarem, si vivere vellet usque ad crucem....Est tanti vulnus suum premere et patibulo pendere districtum.... Invenitur, qui velit adactus ad illud infelix lignum, iam debilis, iam pravus et in foedum scapularum ac pectoris tuber elisus, cui multae moriendi causae etiam citra crucem fuerant, trahere animam tot tormenta tracturam? "I should deem him most despicable had he wished to live up to the very time of crucifixion....Is it worth while to weigh down upon one's own wound, and hang impaled upon a patibulum?....Can any man be found willing to be fastened to the accursed tree, long sickly, already deformed, swelling with ugly tumours on chest and shoulders, and draw the breath of life amid long drawn-out agony? I think he would have many excuses for dying even before mounting the crux!" (Epistle, 101.10-14).
(10) Cogita hoc loco carcerem et cruces et eculeos et uncum et adactum per medium hominem, qui per os emergeret, stipitem. "Picture to yourself under this head the prison, the crux, the rack, the hook, and the stake which they drive straight through a man until it protrudes from his throat" (Epistle, 14.5).
(11) ....sive extendendae per patibulum manus "....or his hands to be extended on a patibulum" (Fragmenta, 124; cf. Lactantius, Divinis Institutionibus, 6.17).
*******This subject is yet another instance of the Society's intellectual dishonesty and failure to represent the sources they quote*******