The Malaysia Airlines earning page is here - https://www.aa.com/i18n/travel-info/...a-airlines.jsp - 1/2 EQM per mile flown and quarter miles as base RDMs and 5% distance as EQDs. I assume therefore that PEK-KUL is 2712 miles.

The earnings are different because you had an AA flight number to PEK and a Malaysia flight number to KUL – earnings are by flight-marketing airline (but not by ticket-selling airline).