I guess we won't know T-O weight compared to E-2? Janes say T-56-427A for JASDF E-2D is 5820 shpWJ-6C and T-56-427 are in the same category.
Y-9's WJ-6Cs are rated at 5100 hp from memory.
The T-56-427 is rated at 5250 hp.
KJ-600 should be using WJ-6C or a close derivative.
In any case it certainly isn't using PW100C or any other engine from a western nation.
I think like T56 the WJ-6 is very proven design flying on many aircraft