On the Nireeka, would like you to consider changing the Shimano groupset to SRAM as an option item with the price difference being paid by the customer.
The 1x12 speed GX Eagle groupset offered by SRAM is impressive power train (with a 500% gear range - 10/50t cassette) that doesn't need a front derailleur - saving weight and costs. It has the grip shift, with the standard paddle shifter to change gears. Review of the GX Eagle is available here: https://www.singletracks.com/blog/mtb-gear/sram-gx-eagle-drivetrain-review/. Offers more chain ring sizes (30t/32t/34t/36t/38t) with a larger ring that's better than what the Shimano 10 speed offers. There's also the option of oval chain ring (32t/34t/36t/38t).
With a 1x12 speed GX Eagle, the chain guard can still be retained.
I'm asking this because the higher gear ratio will allow better accent and decent on terrains with the Nireeka mountain bike.
Edit 1: Bikeradar Youtube video about the GX Eagle is here: https://www.youtube.com/watch?v=Gi2poq1iLrg
Edit 2: Blistergear review including the a great table in gear inches vs. Shimano can be found here: http://blistergearreview.com/gear-reviews/2017-sram-gx-eagle-drivetrain