I’ve read commentaries which suggest the reasoning you’ve posted. There are interesting and the visual of the Arabic and Greek certainly parallel. While I don’t dismiss the suggestion, I find the words “wisdom to count” intriguing.
Thank you for reminding about the Arabic!
The word rendered “count” can also be translated “reckon” or “decide”; the choice “count” being influenced by the perception that chi xi sigma was to be understood as a number.
The word translated “number” is also legitimately translated “multitude”; as in many in reference to peoples or nations. Again, thinking chi xi sigma was supposed to be a number would influence the choice.
If, instead of 666 we read “in the name of Allah” and choose the other translations of “count” and “number” accordingly, we get a reading of Revelation 13:18 that’s more like this:
Here is wisdom. Let him that hath understanding reckon the multitude of the beast: for it is the multitude of a man; and his multitude is “in the name of Allah.”
A modern translation might read
Here is wisdom. Let whoever has understanding reckon [or recognize] the beast’s multitude: for it is a man’s multitude; and his multitude is “in the name of Allah.”
Again, I will be clear: I’m not saying this is The Solution to this puzzlement, but it’s certainly an exploration worth consideration.