This is actually a really great idea, especially since *A has another hub coming online in ATH in the not-too-distant future when Aegean joins this year.

I'm sure you could make it work on the corporate side as far as Turkish and Egyptair are concerned. I don't know about Aegean though - they're a small-ish airline, so I don't know what sort of resources (financial and otherwise) they have available for something like this.