Before a meaningful discussion can be initiated on this subject, one has to understand why the Al Khalid -2 is not being pursued and what are the capabilities required of the 'Haider' tank.
Currently, Pak Army frontline MBT’s are T-80 UD & Al Khalid. Looking at it from the outside, on can only conclude that upgrading of T-80 UD and/or Al-Khalid would not produce a tank that would meet Pak Army requirement beyond next 10 years, hence the need for a new tank nicknamed Al-Haider.
Assuming that with the Western systems, Al Khalid is at par with the Western MBTs in terms firepower and control systems; comparing Al-Khalid to the modern western tanks such as Leopard -2, M1-Abrams & Challenger, first item one notices is the weight. Western MBTs are in the 60 tons class versus Alkhalid's 46 tons. Even the Indian Arjun weighs in at about 58 ton.
As a simple rule, more armour protection means better survivability but more weight and hence more cost. However, a heavier tank makes it less agile. Hence it is a compromise between agility versus survivability. M1-Abrams is an exception because of a shorter response time of the gas turbine engine, but it is a gas guzzler
The other difference is that Western tanks have a crew of 4 whereas Alkhalid has only 3. With more automation, one can possibly manage with 3 crew members. However, in the battle situation, additional crew member means less workload per crew member. Since a lot depends upon the proficiency of the crew, it is logical that crew of 4 would be preferable.
I, therefore, conclude that Al Haider would be a heavier tank with a crew 4 and with much better armour protection.
