What is the different between ekaksana-citta and subitism? (re: Mahasanghika)

The Mahasanghika school is said to have expounded ekaksana-citta, the belief that Buddhas comprehend all dharmas in a single moment. How does this teaching compare to subitism (sudden enlightenment), the belief that Buddhas attain enlightenment instantaneously? Could the Mahasanghika’s view be considered a form of subitism?