Booking a trip to Budapest which requires a connection within Europe. I note that a surprising number of the connecting flights are on small airlines I've never heard of -- not the LCCs but rather what appear to be low-cost subsidiaries of the big carriers. None of these carriers show up on the mileage earning charts of other carriers (in this case specifically Aegean). I assume that none of these carriers earn any miles at all on Aegean, which calculates miles based on the operating carrier, not the carrier who issued the ticket. Is this correct?