The He 178 had a more powerful engine than the E28/39 ( over 1,100lb versus 750 lb of thrust). Both Gloster and Heinkel opted for twin engined follow ups as a basis to make a practicable jet fighter, these being the F9/40 (later Meteor) and the He 280.
The prototype He 280 first flew on April 2 1941, thus before the E28/39 (15 May 1941) and well over two years before the F9/40 ( 13 November 1943).