You're not comparing two treks.

We can show you the numbers, but we'd be doing you a disservice if we didn't say this first: Thamsar Pass Trek and Triund Trek are not alternatives — they are different sports. One is a 8-day experience reaching 15,500ft, the other is 2 days reaching 9,350ft. If you're choosing between these two, one of them likely isn't an option for you yet.