Actuallly the vt4 is technically the export version of the 99a since it utilizes the 99a's techAnyways....
If you subtract the legacy MBTs and the Ukranian T-80s (which are unreliable now because of Ukraine's issues), the only thing that's left are the 350 Al Khalids. This is a bad situation. But this was expected, because the Army willingly took a back seat for a while, to give priority to the PAF and PN in recent years, which is a good thing. It was a worthy sacrifice. Now that both the PAF/PN have stabilized, looks like the Army acquisitions are starting to gather steam again.
I think the Pakistani Army has a requirement of 1500 gen 3 tanks, and 500 gen 3+/4 tanks. It needs to retire all its legacy MBTs (including Al Zarrars.) Our MBT roster is way too clustered right now, and it surely puts a strain on logistics, especially the T-80s. It was just a bad idea to source anything from Ukraine in the first place. Instead of trying to maintain our T-80 fleet, we should mothball them, or sell them off, if anyone will buy them second hand. But it doesn't make much sense to maintain that unreliable logistical supply line only for 300 T-80s, especially since Pakistan is warming up to Russia.
I think a good split would be the following:
1000 - Al Khalid I
500 - VT-4
500 - Altay^ or Type 99A*
And if the Altay or Type 99A are unavailable (*export restrictions) or too expensive (^which they probably will be), than just create another upgrade of the Al Khalid I, add more armor and an APS and get 500 of those (or maybe 500 VT-4s, depending on their available addons). Either way, we should have a minimum of 2000 proper MBTs.