Even smaller than those WS-9? Since the A-5 came from the J-6 and has a solid nose and body, wouldn't it be a good idea to employ it as a fighter also? It can mount a bigger radar if it wishes, fly further, and with 10 hardpoints (well, 8 that works here)/space for it, it would be a much better fighter than the J-7.
Not only its much smaller than the WS-9, its even much smaller than the WP-13, which is a small engine on its own right. And I mean small, you're talking about an engine in the size class as those used in the F-5Es or an advanced trainer.
The Q-5 uses two of these engines (WP-6), and surprisingly the thrust output of a Q-5 or a late model J-6 exceeds that of early and mid generation MiG-21s. Except for a MiG-21bis, which only matches the TWR of a J-6.
The Q-5's nose does not really mount a radar. Experiments to add a radar on its nose, especially one for antishipping use, ended up creating ugly platypuses. The nose of the Q-5 is actually too thin. Compared to the J-6, the thin nose is designed to give an easy downward view---the same principle as the MiG-27. This does not mean the jet cannot dogfight on a visual range level. The Pakistani experience reflects that the plane can dogfight even with F-16As at low altitude.
Back in the seventies when the Q-5 was just coming out, US mags I remember, portrayed the Q-5 like some new Chinese fighter, not as the attack plane it became.
The Q-5's flight characteristics were refined throughout the years, but in the early times it was as difficult to fly as the J-6. The J-7 is a much easier and nice jet to fly. Later, the Q-5;s flight behavior was refined to the ease it is found today but long before it has evolved to its specialized attack role.
In a way, when Q-5 regiments upgrade to the JH-7A, there was their downsides. The Q-5 is a lighter, more nimble, more agile plane with dogfighting characteristics and it had better downward visibility. The Q-5s of an upgraded regiment fortunately, appeared ended up moved to the sister regiments within the same division.
In my view a CAS aircraft caught in low altitude by a Q-5 should expect the fight of their lives.
However there are serious down points on using the Q-5 as a fighter. The nose cone is one, not meant to hold a radar, though it can hold a laser rangefinder. Two turbojets consume a lot of gas more than one turbojet, which consumes more gas than a turbofan. This means the Q-5 has a short endurance. Being a twin engine, its rather complex for a small jet, hence its not a maintenance friendly plane. While its turn rate maybe better than a J-7, its roll rate is not.