Super Mirage G8A/ACF would have been a "F-15 class" fighter (in terms of raw performance) with less advanced aerodynamics.
The original G and G8 were MiG-23 and F-111/F-14A class, respectively.
The decision to replace US-designed TF-30s with French M53s on the G8A gave it superior engines to those of an F-14A. But let's not forget that, while on paper it should have superior raw performance in the air to an F-14A, keep in mind that it would have inferior agility and cockpit visibility, and it was very likely to get inferior weapons and avionics suite.
Speaking of Grumman, an early Grumman FX (pictured below) study showed similar characteristics to the G8A.