We've all seen this, Agrippa's angel sigil chart:
In my opinion, as a person completely unfamiliar with Arabic, these sigils look like a poor attempt to copy otherwise ordinary Arabic writing. Not magical seals, just a copyist who knew about as much Arabic as I do.
Compare these written names to the seals of Gabriel and Raphael, for example:
And here is the seal of Michael:
The same name, Michael, in Arabic:
Then flip it: