I have a "minority" view on the J10CE on this forum. I think it is better to get the first variant of the J-35AE's(ie Block 1? - though i have not seen that specific designation yet) and get rid of the J10CE entirely imho than to get more in this day and age of needing stealth platforms. The logistical, support and maintenance infrastructure for 20 units, probably means we are very reliant on China supporting these planes versus doing them in Pakistan ( we have heard of Chinese engineers on site helping etc). I can't imagine that there is that much setup in Pakistan for the J10CE compared to the F16/Mirages/JF17s etc.
Go big on the J-35AE instead and spend the time to build the logistical, support and maintence infrastructure for the J-35AE in Pakistan and skip the costs for the J-10CE.
The J10CE are virtually new right now as planes go and won't need as much logistical, support and maintenance infrastructure right now compared to when they get to their first service/overhaul/maintenance interval etc.
"IMHO..". At 20 units, there is no sunk cost barrier to work through on the J10CE. Re-sell them to another J10CE operator etc when the J-35AE's turn up.