The max power outputs you see in the engine specs are related to emergency and take-off power. Continuous output powers and optimum operating ranges are different. So it would be very superficial to reduce this issue only to the engine output power.
Also, how did you get the idea that the T-129 was ahead by only one factor in the pre-bid evaluation process and won the tender for that reason alone? Is there a report published by Pakistani authorities on this subject or are you just getting an opinion on forum-level speculative stuff?
T-129 is a armed reconnaissance/attack platform which operative efficiency has been proven in Pakistani field tests and even in TAF military operations closely followed by Pakistani authorities, and there are no soaped figures among its specs. Whatever written in specs, it actually is. Z-10? Undoubtedly a great helicopter. I don't have any criticism about it. But when marketing the Z-10M, it's useless to underestimate the T-129.