Whose under the Motorcraft label will depend on your country. Like every large manufacturer of motor vehicles and power trains, their engineers develop a specification for oil and go through a "bid" process to have a supplier manufacture their private label oil (and other lubricants). Due to various factors like shipping costs, taxes, duty fees, union contracts, treaties, etc., that same private label oil will be produced by different oil company's in different parts of the world. It is up to the vehicle manufacturer to test those oils periodically to ensure they meet the spec.
BTW those Delo oils are pretty good and not just for the budget minded fleet operators...although they are definitely more affordable then many brands that supply fleets, construction and ag equipment operators. I have seen oil analysis results on Delo oils that have come out of turbo diesels that measure up to the more expensive brands. Rotella T5 and T6 heavy duty oils compete with Delo and measure up equally when in service...BUT the oil analysis results will differ in certain areas and that is OK as long as the oil performs as expected.
It's interesting to see how oil discussions can "tickle" almost everybody's fancy.