Congratulations Pakistan. I reckon training launches serve many purposes on top of exercises and that can include shelf-life validation, navigational systems and improved/evasive flight trajectories.
300 KM range is enough for its purpose. India could not lift its head up after losing just two jets to Pakistan. Imagine what this baby would do to them.
The range is sufficient to hit crucial enemy targets beyond the front where reserve invasion forces will have massed to support a breakthrough into our defenses.
As a comparison to a missile of an earlier era.
During World War 2 primitive German V2 missiles with approximately the same range ( 300 km) and warhead capacity ( 1000 kg ) were used against Allied forces in Antwerp and London. These missiles were very inaccurate and the concept of Circular Error of Probability had not even been determined then. Even then the V2s were lethal. Almost 2800 people were killed in London alone. A total of 9000 civilian, and Military deaths were recorded due to V2 attacks in Europe and UK. Those V2s could not be stopped.
Even though modern anti-missile defenses could stop most 1st Generation missiles ( Example: Iraqi Scud missiles being intercepted by M104 Patriot systems ) it would be more difficult to stop a Ghaznavi.
We do know a little how the Scud B
missiles were stopped.
1. Destroying them in the launch preparations phase while on the TELs.
2. Destroying them in the boost phase. Not sure how effective this was.,
3. Destroying Scud warheads as they approached the target.
A comparison:
Being solid fueled, far less preparation and time is needed for the firing cycle ; thus destroying the missile in it's pre-launch positioning mode ( on the TEL) is less easy. The TELs would have a "shoot and scoot ability".
Shooting down in the boost phase is also difficult on account of a higher speed, and much smaller flight time.
The best option for a Patriot or S-300 system would be to try to destroy the warheads.,
The Ghaznavi warhead would likely have some maneuvering ability, making intercepts difficult, and if nuclear likely to detonate in an air burst if tracked and approached by an intercepting missile.,
The above is obviously conjecture as there is less information on how the Ghaznavi actually works.
The Ghaznavi serves an important role as just one of the suite of several types missiles that will be used to retaliate against an enemy missile strike.