CF and MO theories: seeing connections between the two approaches

I wonder if and how when considering MO theory, we are accounting for the electrostatic interaction / repulsion between electrons on the metal and the ligand. It seems like MO assumes pure covalency, so why is this necessarily more accurate than crystal field? 


I am primarily looking for a quantum mechanical explanation of what is accounted for when MOs are being constructed, but any suggestion or indication of the right direction would be great. Thank you! 


