This made me think - CX is going to incur more cost purchasing the miles which are earned in AA / AS / Other programs.
Exactly, DAD-HKG-JFK return in J will generate over 50,000 redeemable miles if credited to AS. Assuming a low-ball valuation of US$0.01 per mile and to keep things simple, that's USD500 per ticket. Even if no cash changes hands, those 50k miles represent another one-way J class award flight on CX in the future (assuming the AS award chart doesn't change).