22626 SBC-MAS Double Decker - எப்பவுமே டாப் டக்கர் - Vijay Baradwaj

No Fool's paradise here. Please don't throw around randoms claims like these. Tractive effort charts are available for all the locomotives online. Please refer to those before making any conclusions.
A WAP7 is 'useless' beyond 140kmph. Its tractive effort falls to 'zero'. It won't have any acceleration reserve left and it cannot haul even a short rake above that speed.
A WAP5 can easily go beyond 180kmph with a short rake, while a WAP7 cannot haul even a short rake beyond 140.
Like...
more...

you said , WAP7 is just a regeared version of the WAG9. It is a very heavy locomotive that is mainly targeted at performing better with long rakes at lower speeds. It is just a freight loco, with no good passenger loco features other than the MPS.
The WAP7 is the 'worst possible design' for a high speed locomotive and the best possible design for hauling long rakes at moderate speeds.
The WAP5 is ONLY locomotive in the country that is suitable for high speeds. It has a lot of features that high speed locos need. The WAP7 doesn't have any of those features. It just has brute force.