More of a minor update, but, since the topic was raised here: after talking about the matter internally, we have decided to move one of the Hellenic holy sites, from Abydos to Syracuse.
From a historical perspective, Syracuse was a fairly important city all the way until the earliest start dates (when its importance starts to wane), and, before Christianity, it was home to several notable Hellenic temples.
From a gameplay perspective, it reduces the clustering of Holy Sites in Greece and gives Italian rulers a more easily accessible holy site to use Delve into the Classics (without needing to wage war against the Papacy/ERE/Egypt).