I'm not an expert in the topic, but it's remarkable how this particular idea has really taken on life of its own. For anyone interested in apocalyptic literature or weird angels, here's a high level explanation.
So a lot of apocalyptic imagery isn't really meant to be taken literally. They represent ideas that were meant to be understood by the recipients.
So the faces of the four creatures represent the sum of all creation.
Covered in eyes implies that God (and his agents) are all seeing.
The wings imply they can move swiftly and be present wherever needed.
Taken together, these images tell us that God has authority over all creation, can see injustice and act swiftly when necessary.
These are just theorized examples, because we can't be 100% sure what the original intent was. The point is that the audience almost certainly understood and received it as such.
This is also true for Revelation, a book rich in apocalyptic imagery, most of which we can make more accurate guesses. For instance, the beast referenced by 666 is most likely Nero Caesar. This theory is supported because there are alternative, ancient versions which use 616.
Here's how the gematria (Hebrew numbering system) supports this theory:
Nero Caesar, in Hebrew, can be transliterated from Greek as נרון קסר (Neron Kesar). Hebrew, unlike English, does not have separate numerical digits, so each letter also serves as a number. Here’s how the calculation works:
If you start with Latin rather than the Greek, Nero’s name is transliterated as נרו קסר (Nero Kesar) in Hebrew, omitting the final ‘n’ (נ) found in “Neron”. The calculation would be as follows:
There you go. Apocalyptic imagery is really weird, but it is coded with intent. This can be difficult as it tends to appeal to the red-stringers in all of us. Good literature, like good science, should never seek to validate assumptions, but to follow the text and apply Occam's Razor liberally.