The problem with your theories is that the Roman alphabet was not used as a numbering scheme like Greek used to be, (where alpha=1, beta=2, gamma=5, delta=4, epsilon=5, stigma (a defunct letter "st") = 6, zeta= 7, eta=8, theta=9, iota=10, kappa=20, etc.). Many words in Greek can literally be interpreted as numbers.
John's 666 is three Greek letters chi-xi-stigma read left-to-right which look remarkably like Arabic (reading right-to-left) for "In the name of Allah" followed by crossed swords! 666 also figures highly in the mythology, symbology, and numerology surrounding the Caliph. John's Antichrist is Islam's leader. It's spooky. John did not encounter Arabic (it came later), but he was shown the symbols that looked to him like Greek letters.