Yes you are right but most of the deals are done already. On the other hand can you deny that India is getting closer to US. politically. Russia with all this investment is loosing influence in India it seems. If all is good between India and Russia, then why there are these rumors of SU-35 sale. We didn't hear such rumors 3-4 years ago.
I can't account for rumors, rumors and gossip usually do not have any logic.
Even without taking into account any of the Indo-Russian ties, anybody could see that Pakistan would not purchase a twin engined, heavy air superiority fighter like the Su-35. That just does not fit into the PAF's doctrine or domain. (Of course, doctrines can change.)
PAF has never operated a fighter of that class - even the IAF did not, until the MKIs entered service. At that time, many in India questioned the need for the IAF to operate such a huge beast, not only expensive to purchase, but to operate. The induction of the MKIs completely changed the IAF's doctrine, from a tactical air force to one that can play a strategic role.
With the tiny budget that the PAF has, I cannot see how it can afford to operate a 20+ tonne jet like the Su-35. It would be possible if more funds are allocated, but is that likely?
The PAF's role as of now is defending Pakistan's airspace - that can be done much more cost-effectively by F-16s, or similar stuff. Maybe the PAF wants to take on a bigger role, and have the capability to do deep strikes inside India - for that they would require a heavy fighter with long endurance and large payload, but even then, the smarter option would be to buy something from China. It would be cheaper, not to mention the fact that Chinese engineers and instructors are already familiar with PAF personnel.
Maybe I'm wrong, maybe the PAF does really intend to get a huge leap in capability - but then comes the question of Russian-Indian relations, and all that geopolitics.
