Maybe the Emerald agents are better trained. But the "AA girls" definitely can look up the AAdvantage earnings certain booking classes on other OW carriers yield.
Also the earning scheme on OW is much simpler than on *A. The most glaring difference is that the booked carrier code counts and not the operating carrier. So occasionally, one can earn miles on CX ...
LH credits your M&M miles, TK just gives LH some compensation for the flight you booked and rode. LH is pretty much 100% at fault for the credit.