You have to remember that seldomly spesific weapon systems are mented to fight against each others. Ofcourse there is some cases where this isen't true, like MBTs and Fighterplanes. But usually weaponsystems are mented to destroy some other non-related systems.
In this case the question is about attack helicopters. Despite how cool they look and sound, they are intended mainly to one or two roles, anti-tank and counter-insurgency. Altough some modern attack choppers have air-to-air weaponry to destroy other helicopters, all current attack copters are designed to be anti-tank platforms in the first place.
Thats the case with both WZ-10 and Ah-64 Apache. If Taiwan recives Apaches it's hardly a "treat" to china when the situation is what it is now. It becomes to threat if China tries to invade Taiwan, as the PLA amphibious assault force is extremely vunarable to aerial threats.
The awnser to this threat is not WZ-10. Its more flexible and capaple aidefence suite for the PLA amphibious force.