Kingdra can't muscle through Ferrothorn like Keldeo can, as well as Draco taking -2 toll and LO wearing it down excessively to the point where rain teams can easily wear it down. Keldeo basically can handle steel types better as well as setting it up easier with its higher base speeds.
Each have their own niche imo. I'll AC mention HP Psychic, glad you like this set ^-^.
QC checks y/n?