If i am not wrong,this is all mybe just a myth,but this is what i think what might happen.
Pak and china sign CPEC
China wants its to be secured,Navy and Army are strengthened but a never ending threat from india from air persists.
India threaten GB and Balochistan.
Pak wants a suitable long range fighter,russian jets is the answer,relations with russia at this time not warm enough.
China orders Su 35 on Paks behalf,so that when pak orders it will take yet another 2 years from them to deliver it,indians at that time might be able to halt the deliveries,if it happens fast the lobbying might not be effective,
China starts training of PAF pilots on Su-30 derivatives.
Pak warms up relations and in turn signs deal for su-35
Su-35 are delivered in a hindsight as they were already produced for PLAAF.
only the last 2 lines haven't been materialised else everything seems the way i wrote.