WS-19 will be available by the time AZM enters prototyping stage. It will be able to generate 10 tonnes of thrust and have a T/W ratio of 10 ... it is also built for supercruise unlike the F135 (which has a high bypass ratio). I don't think suitable engines will be a problem for the AZM at all given the faster than expected progress of the WS-19.
The engine choice will say a lot about AZM.
Remember, the requirement is for a twin-engine design with super-cruising.
IMO ... if it's the WS-19, then the PAF is clearly looking at a medium-weight fighter. But while having an in-house fighter is admirable and all, what would be the point if there's also the similar J-35? You can certainly roll the two into one, but as we clearly see from the concepts, AZM isn't (at least for now) a J-31-derived design.
However, if they select a WS-10 variant or WS-15, then the PAF is looking at a heavyweight.
In that case, the PAF is clearly fulfilling a need it'd unlikely be able to fill with an import (as buying such fighters from abroad is either not an option, or too expensive). But it'd also be infeasible to center the entire fleet on that large a jet, so that opens the door up to a medium-weight.
How about ...
2030-2045: J-35 as a mainstay medium-weight (120~180 units)?
2035-2045: AZM as a deep-strike-capable 5+ gen platform (50~90 units)?
This outcome also makes some industrial sense too. If Pakistan is manufacturing the AZM turn-key (even with imported engines and materials), do we honestly think it's going to roll out more than 8-12 jets per year? It's rolling out 16 JF-17s per year (against a stated capacity of 24) on a co-production basis with half coming from China.
So, I can see a production run for even 100 AZMs rolling for 15+ years, especially with the lightweight industrial set-up we have in Pakistan. This is especially so if we start relying on the private sector. I want our businesses to succeed, but there's no way we'll see them manufacture fast enough for 15-20 AZMs per year.