When i look at the specs i see Viper , T-129 and Z-10 all three of them got at least 1000 m higher service ceiling than Mi-35 so i still believe Pakistan shouldn't go for this heli.
Respective service ceilings:
Viper 6,000+ m (20,000+ ft)
T-129 6,100 m (20,000 ft)
Z-10 6,400 m
Mi-35 4,900...