Alot of unit AOR are messed up. For instance, there are a number of provinces where KH cannot recruit Iphikratous Hoplitai but can recruit Thorakitai Hoplitai, which are the heavier/richer version of the Iphikrateans. Also, KH cannot Massillian Hoplites in their factional MIC, which seems odd to me as they are a Hellenic unit. IIRC, the Indian Spearmen aren't recruitable at all for any faction, and certainly both Ethiopian Swordsmen and Agema (the two-handed axemen) are never recruitable. Red Sea Hoplties are only recruitable in Arabia, and not by the Ptolemaioi.

So I'd say it's just the result of oversight by the EB coders. Having taken a look at how their recruitment system is coded, it is quite daunting, requires alot of copy-paste-edit work to write (or modify) and so it's extremely easy to forget a province when you want to change an AOR.