You've yourself noted PAF will miss its target of induction by 2030 by a decade. Which means either they are incompetent or the analysis is wrong.
Yes the analysis can be wrong, that's what it is, an inference based on the available info. But by that reasoning, I can't preclude the possibility that the PAF never intended to get its own homegrown fighter by the 2030s. Rather, it had been open to adopting an off-the-shelf design in the interim from the start -- neither of us know for sure, but a possibility like that would preclude incompetence.
The argument you are using can equally be used against your position - PAF has clearly stated it is a clean sheet design. If the adopt the J-31 - they are contradicting themselves, - far more than whether the clean sheet design should be single engined or twin engined.
Yes, there can be a clean-sheet design, fair, but how do we know that the goal is to materialize that design by 2030? The PAF said it wants an FGFA by around 2030, be it in-house or a consortium/partnership (since both ACM Aman and ACM Mujahid raised the the latter as a possibility).
But we know (through engineers with experience working on Pakistani defence projects) that an in-house project won't come to fruition that soon, which leaves us with an off-the-shelf/consortium option.
And BTW, I noticed you think the PAF is buying J-10s or J-15s off-the-shelf, if you believe in that, then you have to accept the off-the-shelf FGFA possibility too. It's ultimately the same issue, i.e., slotting in an off-the-shelf purchase of some kind (be it a total purchase OR consortium) in the interim until AZM materializes.
Additionally, imagine this: PAF, as you suggest, goes for J-31 and starts inducting them around 2025-2030. Then, using the same twin engines, develops an aircraft near identical to the J-31, a decade and half later... That would not make sense at all.
If the J-31E can meet the twin-engine need, it can change the ASR for AZM. Or, it could stick with the twin-engine, in-house design. It might be redundant from a general capability standpoint, but the in-house fighter would involve actual Pakistani technologies, which is the real gain. Heck, the manned fighter at that point may not even the main outcome, those Pakistani technologies could flow into UAV/UCAVs, for example, or some other program.
BTW ... the inclusion of J-31 could strengthen your analysis of AZM ultimately being a single-engine jet. Which is my original point, that the near-term FGFA requirement is for a twin-engine jet (which leaves the FC-31 as the most realistic option), while in the background, AZM can be a single-engine design that comes much later on.
