Yes, most ground strikes were by other aircraft types, but the F-15E did have a lot of sorties, almost as many as the F-111 or F-4G (although the F-16 had many, many more sorties, but not all of them were air-to-ground)

Source is the Gulf War Airpower Survey, page 184 (PDF page 205): https://apps.dtic.mil/sti/tr/pdf/ADA273996.pdf